17 Understanding Oracle ACFS Advanced Topics

Oracle ACFS advanced topics include discussions about more complex administrative issues.

This appendix discusses Oracle Automatic Storage Management Cluster File System (Oracle ACFS) advanced topics, including limits, advanced administration, and troubleshooting.

See Also:

Articles available at My Oracle Support (https://support.oracle.com) for information about Oracle ACFS and Oracle ADVM.

This appendix contains the following topics:

For an overview of Oracle ACFS, see Introducing Oracle ACFS and Oracle ADVM.

Limits of Oracle ACFS

The limits of Oracle ACFS are discussed in this section.

The topics contained in this section are:

Note:

Oracle ACFS does not support hard links on directories.

Oracle ACFS Disk Space Usage

Oracle ACFS supports 64 mounted file systems on 32-bit systems, and 256 mounts on 64-bit systems. However, more file systems can be mounted if there is adequate memory.

Oracle ACFS supports 2^40 (1 trillion) files in a file system. More than 4 billion files have been tested. There is no absolute limit to the number of directories in a file system; the limit is based on hardware resources.

Oracle ACFS preallocates large user files to improve performance when writing data. This storage is not returned when the file is closed, but it is returned when the file is deleted. Oracle ACFS also allocates local metadata files as nodes mount the file system for the first time. This can result in a mount failing due to an out of space error, and much of this storage must be contiguous. This storage is approximately 64-128 megabytes per node.

Oracle ACFS also keeps local bitmaps available to reduce contention on the global storage bitmap when searching for free space. This disk space is reported as in use by tools such as the Linux df command even though some space may not actually be allocated yet. This local storage pool can be as large as 128 megabytes per node and can allow space allocations to succeed, even though commands, such as df, report less space available than what is being allocated.

For Oracle ACFS 12.2.0.1, the maximum size that can be allocated to an Oracle ACFS file system is 128 terabytes (TB), as shown in Table 17-1. The storage limits for Oracle ACFS and Oracle ASM are dependent on disk group compatibility attributes.

Table 17-1 Maximum file sizes for Oracle ADVM volumes

Redundancy Disk Group with COMPATIBLE.ASM < 12.2.0.1 Disk Group with COMPATIBLE.ASM = 12.2.0.1

External

128 TB

128 TB

Normal

64 TB

128 TB

High

42.6 TB

128 TB

See Also:

Oracle ACFS Error Handling

Oracle ASM instance failure or forced shutdown while Oracle ACFS or another file system is using an Oracle ADVM volume results in I/O failures. The volumes must be closed and re-opened to access the volume again. This requires dismounting any file systems that were mounted when the local Oracle ASM instance failed. After the instance is restarted, the corresponding disk group must be mounted with the volume enabled followed by a remount of the file system. See "Deregistering, Dismounting, and Disabling Volumes and Oracle ACFS File Systems".

If any file systems are currently mounted on Oracle ADVM volume files, the SHUTDOWN ABORT command should not be used to terminate the Oracle ASM instance without first dismounting those file systems. Otherwise, applications encounter I/O errors and Oracle ACFS user data and metadata being written at the time of the termination may not be flushed to storage before the Oracle ASM storage is fenced. If there is not time to permit the file system to dismount, then you should run two sync (1) commands to flush cached file system data and metadata to persistent storage before issuing the SHUTDOWN ABORT operation.

Oracle ACFS does not interrupt the operating system environment when a metadata write fails, whether due to Oracle ASM instance failure or storage failure. Instead, Oracle ACFS isolates errors to a specific file system, putting it in an offline error state. The only operation that succeeds on that node for that file system from that point forward is a dismount operation. Another node recovers any outstanding metadata transactions, assuming it can write the metadata out to the storage. It is possible to remount the file system on the offlined node after the I/O condition is resolved.

It might not be possible for an administrator to dismount a file system while it is in the offline error state if there are processes referencing the file system, such as a directory of the file system being the current working directory for a process. To dismount the file system in this case it would be necessary to identify all processes on that node with references to files and directories on the file system and cause them to exit. The Linux fuser or lsof commands or Window handle command list information about processes and open files.

If Oracle ACFS detects inconsistent file metadata returned from a read operation, based on checksum or expected type comparisons, Oracle ACFS takes the appropriate action to isolate the affected file system components and generate a notification that fsck or acfschkdsk should be run as soon as possible. Each time the file system is mounted a notification is generated with a system event logger message until fsck or acfschkdsk is run.

Oracle ACFS and NFS

When exporting file systems through NFS on Linux, use the -fsid=num exports option. This option forces the file system identification portion of the file handle used to communicate with NFS clients to be the specified number instead of a number derived from the major and minor number of the block device on which the file system is mounted. You can use any 32-bit number for num, but it must be unique among all the exported file systems. In addition, num must be unique among members of the cluster and must be the same num on each member of the cluster for a given file system. This is needed because Oracle ASM DVM block device major numbers are not guaranteed to be the same across restarts of the same node or across different nodes in the cluster.

When using High Availability NFS for Grid Home Clusters (HANFS), HANFS automatically handles the situation described in the previous paragraph. For information about HANFS, refer to "High Availability Network File Storage for Oracle Grid Infrastructure".

Limits of Oracle ADVM

The limits of Oracle ADVM and these discussed in this section.

The default configuration for an Oracle ADVM volume is 8 columns and a 1 MB stripe width. The volume extent size is 8 megabytes (MB) if the disk group allocation unit (AU) is less than or equal to 8 MB. If the AU size is greater than 8 MB, then the Oracle ADVM volume extent size is equivalent to the disk group AU size.

Oracle ADVM writes data as 1 megabyte (MB) stripe chunks in round robin fashion to each column and fills a stripe set of eight 8 MB extents with 64 stripe chunks before moving to a second stripe set of eight 8 MB extents for volumes greater than 64 MB. Setting the number of columns on an Oracle ADVM dynamic volume to 1 effectively turns off striping for the Oracle ADVM volume.

On Linux platforms Oracle ASM Dynamic Volume Manager (Oracle ADVM) volume devices are created as block devices regardless of the configuration of the underlying storage in the Oracle ASM disk group. Do not use raw (8) to map Oracle ADVM volume block devices into raw volume devices.

For information about ASMCMD commands to manage Oracle ADVM volumes, refer to Managing Oracle ADVM with ASMCMD .

Oracle ACFS Loopback Support

Oracle ACFS supports loopback functionality on the Linux operating system, enabling Oracle ACFS files to be accessed as devices.

An Oracle ACFS loopback device is an operating system pseudo-device that enables an Oracle ACFS file to be accessed as a block device. This functionality can be used with Oracle Virtual Machines (OVM) in support of OVM images, templates, and virtual disks (vdisks) created in Oracle ACFS file systems and presented through Oracle ACFS loopback devices.

Oracle ACFS loopback functionality provides performance gains over NFS. Files can be sparse or non-sparse.

In addition to general loopback support, Oracle ACFS also provides support for loopback direct I/O (DIO) on sparse images.

Oracle ACFS Drivers Resource Management

Oracle ACFS, Oracle ADVM, and OKS drivers are loaded during the start of the Oracle Grid Infrastructure stack, except in an Oracle Restart configuration. The drivers remain loaded until the system is rebooted, at which point, they are loaded again when the Oracle Grid Infrastructure stack restarts.

For information about commands to manage Oracle ACFS, Oracle ADVM, and OKS drivers, refer to "Oracle ACFS Driver Commands".

Oracle ACFS Registry Resource Management

The Oracle ACFS registry resource is supported only for Oracle Grid Infrastructure cluster configurations; it is not supported for Oracle Restart configurations. See "Oracle ACFS and Oracle Restart".

With Oracle ASM 12c Release 1 (12.1), the Oracle ACFS registry uses the standard single file system resource available through the SRVCTL file system interface. For more information, refer to "Oracle ACFS File System Resource Management". Using SRVCTL enables applications to depend on registered file systems, such as for management of the registered file systems using srvctl filesystem. By default, acfsutil registry shows only file systems that are set to be always mounted, with the AUTO_START attribute set to always.

The Oracle ACFS registry requires root privileges to register and delete file systems, however, other users can be entitled to start and stop (mount and unmount) the file systems by use of the user option.

Oracle ACFS File System Resource Management

The Oracle ACFS file system resource is supported only for Oracle Grid Infrastructure cluster configurations; it is not supported for Oracle Restart configurations. See "Oracle ACFS and Oracle Restart".

Oracle ASM Configuration Assistant (ASMCA) facilitates the creation of Oracle ACFS file system resources (ora.diskgroup.volume.acfs). During database creation with Database Configuration Assistant (DBCA), the Oracle ACFS file system resource is included in the dependency list of its associated disk group so that stopping the disk group also attempts to stop any dependent Oracle ACFS file systems.

An Oracle ACFS file system resource is typically created for use with application resource dependency lists. For example, if an Oracle ACFS file system is configured for use as an Oracle Database home, then a resource created for the file system can be included in the resource dependency list of the Oracle Database application. This dependency causes the file system and stack to be automatically mounted due to the start action of the database application.

The start action for an Oracle ACFS file system resource is to mount the file system. This Oracle ACFS file system resource action includes confirming that the associated file system storage stack is active and mounting the disk group, enabling the volume file, and creating the mount point if necessary to complete the mount operation. If the file system is successfully mounted, the state of the resource is set to online; otherwise, it is set to offline.

The check action for an Oracle ACFS file system resource verifies that the file system is mounted. It sets the state of the resource to online status if mounted, otherwise the status is set to offline.

The stop action for an Oracle ACFS file system resource attempts to dismount the file system. If the file system cannot be dismounted due to open references, the stop action displays and logs the process identifiers for any processes holding a reference.

Use of the srvctl start and stop actions to manage the Oracle ACFS file system resources maintains their correct resource state.

Oracle ACFS and Oracle Restart

Oracle Restart does not support root-based Oracle ACFS resources for this release. Consequently, the following operations are not automatically performed:

  • Loading Oracle ACFS drivers

    You can load or unload the drivers manually with the acfsload command. For more information, refer to "acfsload".

  • Mounting Oracle ACFS file systems listed in the Oracle ACFS mount registry

    You can mount Oracle ACFS file systems manually with the mount command. For information, refer to Managing Oracle ACFS with Command-Line Tools.

  • Mounting resource-based Oracle ACFS database home file systems

The Oracle ACFS resources associated with these actions are not created for Oracle Restart configurations.

While Oracle ACFS resource management is fully supported for Oracle Grid Infrastructure configurations, the Oracle ACFS resource-based management actions must be replaced with alternative, sometimes manual, operations in Oracle Restart configurations.

Oracle ACFS Driver Commands

This section describes the Oracle ACFS driver commands that are used during installation to manage Oracle ACFS, Oracle ADVM, and Oracle Kernel Services Driver (OKS) drivers. These commands are located in the /bin directory of the Oracle Grid Infrastructure home.

acfsload

Purpose

acfsload loads or unloads Oracle ACFS, Oracle ADVM, and Oracle Kernel Services Driver (OKS) drivers.

Syntax

acfsload { start | stop  } [ -s ]

Table 17-2 contains the options available with the acfsload command.

Table 17-2 Options for the acfsload command

Option Description

start

Loads the Oracle ACFS, Oracle ADVM, and OKS drivers.

stop

Unloads the Oracle ACFS, Oracle ADVM, and OKS drivers.

-s

Operate in silent mode.

Description

You can use acfsload to manually load or unload the Oracle ACFS, Oracle ADVM, and OKS drivers.

Before unloading drivers with the stop option, you must dismount Oracle ACFS file systems and shut down Oracle ASM. For information about dismounting Oracle ACFS file systems, refer to "Deregistering, Dismounting, and Disabling Volumes and Oracle ACFS File Systems".

root or administrator privilege is required to run acfsload.

Examples

The following is an example of the use of acfsload to stop (unload) all drivers.

# acfsload stop

acfsdriverstate

Purpose

acfsdriverstate provides information on the current state of the Oracle ACFS, Oracle ADVM, and Oracle Kernel Services Driver (OKS) drivers.

Syntax

acfsdriverstate [-orahome ORACLE_HOME ] 
    { installed | loaded | version | supported } [-s]

Table 17-3 contains the options available with the acfsdriverstate command.

Table 17-3 Options for the acfsdriverstate command

Option Description

-orahome ORACLE_HOME

Specifies the Oracle Grid Infrastructure home in which the user has permission to execute the acfsdriverstate command.

installed

Determines whether Oracle ACFS is installed on the system.

loaded

Determines whether the Oracle ADVM, Oracle ACFS, and OKS drivers are loaded in memory.

version

Reports the currently installed version of the Oracle ACFS system software.

supported

Reports whether the system is a supported kernel for Oracle ACFS.

-s

Specifies silent mode when running the command.

Description

You can use acfsdriverstate to display detailed information on the current state of the Oracle ACFS, Oracle ADVM, and OKS drivers.

Examples

The following is an example of the use of acfsdriverstate.

$ acfsdriverstate version
ACFS-9325:     Driver OS kernel version = 2.6.39-400.3.0.el6uek.x86_64(x86_64).
ACFS-9326:     Driver Oracle version = 150728.
ACFS-9212:     Driver build version = MAIN.

Oracle ACFS Plug-in Generic Application Programming Interface

Oracle ACFS plug-in operations are supported through a common, operating system (OS) independent file plug-in (C library) application programming interface (API).

The topics contained in this section are:

For more information about Oracle ACFS plug-ins, refer to "Oracle ACFS Plugins".

Oracle ACFS Pre-defined Metric Types

Oracle ACFS provides the ACFSMETRIC1_T and ACFSMETRIC2_T pre-defined metric types.

The ACFSMETRIC1_T metric set is defined for the storage virtualization model. The metrics are maintained as a summary record for either a selected set of tagged files or all files in the file system. Oracle ACFS file metrics include: number of reads, number of writes, average read size, average write size, minimum and maximum read size, minimum and maximum write size, and read cache (VM page cache) hits and misses.

Example:

typedef struct _ACFS_METRIC1 {
    ub2      acfs_version;
    ub2      acfs_type;
    ub4      acfs_seqno;
    ub8      acfs_nreads;
    ub8      acfs_nwrites;
    ub8      acfs_rcachehits;
    ub4      acfs_avgrsize;
    ub4      acfs_avgwsize;
    ub4      acfs_minrsize;
    ub4      acfs_maxrsize;
    ub4      acfs_minwsize;
    ub4      acfs_maxwsize;
    ub4      acfs_rbytes_per_sec;
    ub4      acfs_wbytes_per_sec;
    ub8      acfs_timestamp;
    ub8      acfs_elapsed_secs;
} ACFS_METRIC1;

The ACFSMETRIC2_T is a list of Oracle ACFS write description records containing the fileID, starting offset, size, and sequence number of each write. The sequence number preserves the Oracle ACFS write record order as preserved by the plug-in driver. The sequence number provides a way for applications to order multiple message buffers returned from the API. It also provides detection of dropped write records due to the application not draining the message buffers fast enough through the API.

The write records are contained within multiple in-memory arrays. Each array of records may be fetched with the API with a buffer size currently set to 1 M. At the beginning of the fetched ioctl buffer is a struct which describes the array, including the number of records it contains. The kernel buffers drop the oldest write records if the buffers are filled because the buffers are not being read quickly enough.

Example:

typedef struct _ACFS_METRIC2 {
  ub2              acfs_version;
  ub2              acfs_type;
  ub4              acfs_num_recs;
  ub8              acfs_timestamp;
  ACFS_METRIC2_REC acfs_recs[1];
} ACFS_METRIC2;

typedef struct _ACFS_FILE_ID {
  ub8              acfs_fenum;
  ub4              acfs_genum;
  ub4              acfs_reserved1;
}

typedef struct _ACFS_METRIC2_REC {
  ACFS_FILE_ID     acfs_file_id;
  ub8              acfs_start_offset;
  ub8              acfs_size;
  ub8              acfs_seq_num;
} ACFS_METRIC2_rec;

Oracle ACFS Plug-in APIs

Purpose

The Oracle ACFS plug-in application programming interface (API) sends and receives messages to and from the local plug-in enabled Oracle ACFS driver from the application plug-in module.

Syntax

sb8 acfsplugin_metrics(ub4 metric_type,
  ub1 *metrics,
  ub4 metric_buf_len,
  oratext *mountp );
sb8 acfsfileid_lookup(ACFS_FILEID file_id,
  oratext *full_path,
  oratext *mountp );

Description

The acfsplugin_metrics API is used by an Oracle ACFS application plug-in module to retrieve metrics from the Oracle ACFS driver. The Oracle ACFS driver must first be enabled for plug-in communication using the acfsutil plugin enable command. The selected application plug-in metric type model must match the plug-in configuration defined with the Oracle ACFS plug-in enable command. For information about the acfsutil plugin enable command, refer to "acfsutil plugin enable". The application must provide a buffer large enough to store the metric structures described in "Oracle ACFS Pre-defined Metric Types".

If the provided buffer is NULL and metric_buf_len = 0, the return value is the size required to hold all the currently collected metrics. The application can first query Oracle ACFS to see how big a buffer is required, then allocate a buffer of the necessary size to pass back to Oracle ACFS.

The mount path must be provided to the API to identify the plug-in enabled Oracle ACFS file system that is being referenced.

A nonnegative value is returned for success: 0 for success with no more metrics to collect, 1 to indicate that more metrics are available, or 2 to indicate that no new metrics were collected during the interval. In the case of an error, a negative value is returned and errno is set on Linux environments or SetLastError is called on Windows.

When using metric type #2, the returned metrics include an ACFS_FILE_ID, which contains the fenum and genum pair. In order to translate from the fenum and genum pair to a file path, the application can use acfsfileid_lookup. The application must provide a buffer of length ACFS_FILEID_MAX_PATH_LEN to hold the path. If there are multiple hard links to a file, the returned path is the first one. This is same behavior when using acfsutil info id.

System administrator or Oracle ASM administrator privileges are required to send and receive messages to and from the plug-in enabled Oracle ACFS file system driver.

Writing Applications

To use the plugin API, applications must include the C header file acfslib.h which defines the API functions and structures.

#include <acfslib.h>

When building the application executable, the application must be linked with the acfs12 library. Check the platform-specific documentation for information about environment variables that must be defined. For example:

export LD_LIBRARY_PATH=${ORACLE_HOME}/lib:$
{LD_LIBRARY_PATH}

Then when linking, add the -lacfs12 flag.

Examples

In Example 17-1, the command enables an Oracle ACFS file system mounted on /humanresources for the plug-in service.

Example 17-1 Application Plug-in for Storage Visibility: Poll Model

$ /sbin/acfsutil plugin enable -m acfsmetric1 -t HRDATA /humanresources

With this command, the application plug-in polls the Oracle ACFS plug-in enabled driver for summary metrics associated with files tagged with HRDATA. The application code includes the following:

#include <acfslib.h>
...
/* allocate message buffers */
ACFS_METRIC1 *metrics = malloc (sizeof(ACFS_METRIC1));
/* poll for metric1 data */
while (condition) {
  /* read next summary message from ACFS driver */
   if ((rc = acfsplugin_metrics(ACFS_METRIC_TYPE1,(ub1*)metrics,sizeof(*metrics),
        mountp)) < 0) {
        perror("….Receive failure … ");
        break;
   }
   /* print message data */
   printf ("reads %8llu ", metrics->acfs_nreads);
   printf("writes %8llu ", metrics->acfs_nwrites);
   printf("avg read size %8u ", metrics->acfs_avgrsize);
   printf("avg write size %8u ", metrics->acfs_avgwsize);
   printf("min read size %8u ", metrics->acfs_minrsize);
   printf("max read size %8u ", metrics->acfs_maxrsize);
   ...
   sleep (timebeforenextpoll);
}

In Example 17-2, the command enables an Oracle ACFS file system mounted on /humanresources for the plug-in service.

Example 17-2 Application Plug-in for File Content: Post Model

$ /sbin/acfsutil plugin enable -m acfsmetric1 -t HRDATA -i 5m /humanresources

With this command, every 5 minutes the Oracle ACFS plug-in enabled driver posts file content metrics associated with files tagged with HRDATA. In the application code, the call to acfsplugin_metrics() is blocked until the metrics are posted. The application code includes the following:

#include <acfslib.h>
...
 ACFS_METRIC1 *metrics = malloc (sizeof(ACFS_METRIC1));
 
 /* Wait for metric Data */
  while (condition) {
    /* Wait for next file content posting from ACFS driver */
    rc = ACFS_PLUGIN_MORE_AVAIL;
    /* A return code of 1 indicates that more metrics are available
    * in the current set of metrics.
    */
    while( rc == ACFS_PLUGIN_MORE_AVAIL) {
      /* This call blocks until metrics are available. */
      rc = acfsplugin_metrics(ACFS_METRIC_TYPE1,(ub1*)metrics,sizeof(*metrics),
           mountp);
      if (rc < 0) {
        perror("….Receive failure … ");
        break;
      } else if (rc == ACFS_PLUGIN_NO_NEW_METRICS) {
        printf("No new metrics available.");
        break;
     }
     if (last_seqno != metrics->acfs_seqno-1 ) {
       printf("Warning: Unable to keep up with metrics collection.");
       printf("Missed %d sets of posted metrics.",
              (metrics->acfs_seqno-1)-last_seqno);
     }

      /* print message data */ 
      printf ("reads %8llu ", metrics->acfs_nreads);
      printf("writes %8llu ", metrics->acfs_nwrites);
      printf("avg read size %8u ", metrics->acfs_avgrsize);
      printf("avg write size %8u ", metrics->acfs_avgwsize);
      printf("min read size %8u ", metrics->acfs_minrsize);
      printf("max read size %8u ", metrics->acfs_maxrsize);
      ...
 
      last_seqno = metrics->acfs_seqno;
    }
  }
 
  free(metrics);

Example 17-3 Application for Resolving the File Path from a Fenum and Genum Pair

The following example shows how an application resolves a file path from an Oracle ACFS Metric Type 2 record’s fenum and genum pair.

#include <acfslib.h>
. . .
ACFS_FILE_ID file_id;
char path[ACFS_FILEID_MAX_PATH_LEN];
#ifdef WINDOWS
    file_id.acfs_fenum = atoi(argv[1]);
    file_id.acfs_genum = atoi(argv[2]);
#else
    file_id.acfs_fenum = strtoull(argv[1], 0, 0);
    file_id.acfs_genum = strtoul(argv[2], 0, 0);
#endif
mount_point = argv[3];
sts = acfsfileid_lookup(file_id, path, ACFS_FILEID_MAX_PATH_LEN,
                        mount_point, 0);
if (sts < 0)
 {
 . . .
 }
printf("%s\n", path)

Oracle ACFS Tagging Generic Application Programming Interface

Oracle ACFS tagging operations are supported through a common operating system (OS) independent file tag (C library) application programming interface (API).

An Oracle ACFS tagging API demonstration utility is provided. The demo provides instructions to build the utility with a makefile on each supported platform.

On Solaris, Oracle ACFS tagging APIs can set tag names on symbolic link files, but backup and restore utilities do not save the tag names that are explicitly set on the symbolic link files. Also, symbolic link files lose explicitly set tag names if they have been moved, copied, tarred, or paxed.

The following files are included:

  • $ORACLE_HOME/usm/public/acfslib.h

  • $ORACLE_HOME/usm/demo/acfstagsdemo.c

  • $ORACLE_HOME/usm/demo/Makefile

    Linux, Solaris, or AIX makefile for creating the demo utility.

  • $ORACLE_HOME/usm/demo/MAKEFILE

    Windows demo utility MAKEFILE (for use by the nmake utility) to create the demo utility.

The topics contained in this section are:

Oracle ACFS Tag Name Specifications

An Oracle ACFS tag name can be from 1 to 32 characters in length and consist of a combination of the following set of characters only:

  • uppercase and lowercase alphabetic characters (A-Z, a-z)

  • numbers (0-9)

  • hyphen (-)

  • underscore (_)

  • blank (space)

Oracle ACFS Tagging Error Values

The following are the values for Linux, Solaris, or AIX errno in case of failure:

  • EINVAL – The tag name syntax is invalid or too long.

  • ENODATA – The tag name does not exist for this file or directory.

  • ERANGE - The value buffer is too small to hold the returned value.

  • EACCES – Search permission denied for a directory in the path prefix of path; or the user does not have permission on the file to read tag names.

  • ENAMETOOLONG – The file name is too long.

  • ENOENT – A component of path does not exist.

The following are the values that Windows GetLastError() returns in case of failure:

  • ERROR_INVALID_PARAMETER - The tag name does not exist for this file or directory or the tag name is syntactically incorrect.

  • ERROR_INSUFFICIENT_BUFFER - The value buffer is too small to hold the returned value.

  • ERROR_ACCESS_DENIED - Search permission denied for a directory in the path prefix of path; or the user does not have permission on the file to read tag names.

  • ERROR_INVALID_NAME - The file name or path name is too long or is malformed.

  • ERROR_FILE_NOT_FOUND - The system cannot find the file specified.

acfsgettag

Purpose

Retrieves the value associated with an Oracle ACFS file tag name.

Syntax

sb8 acfsgettag(const oratext *path, const oratext *tagname, oratext *value, 
               size_t size, ub4 flags);

Table 17-4 contains the options available with the acfsgettag command.

Table 17-4 Options for the acfsgettag command

Option Description

path

Specifies a pointer to a file or directory path name.

tagname

Specifies a pointer to a NULL-terminated Oracle ACFS tag name in the format of a valid tag name for regular files and directories.

value

Specifies the memory buffer to retrieve the Oracle ACFS tag value.

size

Specifies the byte size of the memory buffer that holds the returned Oracle ACFS tag value.

flags

Reserved for future use. Must be set to 0.

Description

The acfsgettag library call retrieves the value string of the Oracle ACFS tag name. The return value is the nonzero byte length of the output value string on success or ACFS_TAG_FAIL on failure. For information about operating system-specific extended error information values that may be obtained when an ACFS_TAG_FAIL is returned, refer to "Oracle ACFS Tagging Error Values".

Because Oracle ACFS tag names currently use a fixed value string of 0 (the number zero character with a byte length of one) the value is the same for all Oracle ACFS tag name entries. The size of the value buffer can be determined by calling acfsgettag with a NULL value and 0 size. The library call returns the byte size necessary to hold the value string of the tag name. acfsgettag returns an ENODATA error when the tag name is not set on the file.

Examples

Example 17-4 is an example of the use of the acfsgettag function call.

Example 17-4 Retrieving a file tag value

sb8 rc;
size_t size;
oratext value[2];
const oratext *path = "/mnt/dir1/dir2/file2";
const oratext *tagname = "patch_set_11_1";
size = 1; (byte)
memset((void *)value, 0, 2*sizeof(oratext));
rc = acfsgettag (path, tagname, value, size, 0);
If (rc == ACFS_TAG_FAIL)
  /* check errno or GetLastError() to process error returns /*

acfslisttags

Purpose

Lists the tag names assigned to an Oracle ACFS file. For additional information, refer to "acfsutil tag info".

Syntax

sb8 acfslisttags(const oratext *path, oratext *list, size_t size, ub4 flags);

Table 17-4 contains the options available with the acfslisttags command.

Table 17-5 Options for the acfslisttags command

Option Description

path

Specifies a pointer to a file or directory path name.

list

Specifies a pointer to a memory buffer containing the list of Oracle ACFS tag names.

size

Specifies the size (bytes) of the memory buffer that holds the returned Oracle ACFS tag name list.

flags

Reserved for future use. Must be set to 0.

Description

The acfslisttags library call retrieves all the tag names assigned to an Oracle ACFS file. acfslisttags returns a list of tag names into the list memory buffer. Each tag name in the list is terminated with a NULL. If a file has no tag names then the list is empty. The memory buffer must be large enough to hold all of the tag names assigned to an Oracle ACFS file.

An application must allocate a buffer and specify a list size large enough to hold all of the tag names assigned to an Oracle ACFS file. An application can optionally obtain the list buffer size needed by first calling acfslisttags with a zero value buffer size and NULL list buffer. The application then checks for nonzero, positive list size return values to allocate a list buffer and call acfslisttags to retrieve the actual tag name list.

On success, the return value is a positive byte size of the tag name list or 0 when the file has no tag names. On failure, the return value is ACFS_TAG_FAIL. For information about operating system-specific extended error information values that may be obtained when an ACFS_TAG_FAIL is returned, refer to "Oracle ACFS Tagging Error Values".

Examples

Example 17-5 is an example of the use of the acfslisttags function call.

Example 17-5 Listing file tags

sb8 listsize;
sb8 listsize2;
const oratext *path = "/mnt/dir1/dir2/file2";
oratext *list;
/* Determine size of buffer to store list */
listsize = acfslisttags (path, NULL, 0, 0);
if (listsize == ACFS_TAG_FAIL)
/* retrieve the error code and return */

if (listsize)
{
    list = malloc(listsize)
    /* Retrieve list of tag names */
    listsize2 = acfslisttags (path, list, listsize, 0);
    if (listsize2 == ACFS_TAG_FAIL)
        /* check errno or GetLastError() to process error returns */
    if (listsize2 > 0)
        /* file has a list of tag names to process */
    else
        /* file has no tag names. */
}
else
/* file has no tag names. */

acfsremovetag

Purpose

Removes the tag name on an Oracle ACFS file.

Syntax

sb8 acfsremovetag(const oratext *path, const oratext *tagname, ub4 flags);

Table 17-6 contains the options available with the acfsremovetag command.

Table 17-6 Options for the acfsremovetag command

Option Description

path

Specifies a pointer to a file or directory path name.

tagname

Specifies a pointer to a NULL-terminated Oracle ACFS tag name in the format of a valid tag name for regular files and directories.

flags

Reserved for future use. Must be set to 0.

Description

The acfsremovetag library call removes a tag name on an Oracle ACFS file. The return value is ACFS_TAG_SUCCESS or ACFS_TAG_FAIL. For information about operating system-specific extended error information values that may be obtained when an ACFS_TAG_FAIL is returned, refer to "Oracle ACFS Tagging Error Values".

Examples

Example 17-6 is an example of the use of the acfsremovetag function call.

Example 17-6 Removing file tags

sb8 rc;
const oratext *path= "/mnt/dir1/dir2/file2";
const oratext *tagname = "patch_set_11_1";
rc = acfsremovetag (path, tagname, 0);
If (rc == ACFS_TAG_FAIL)
  /* check errno or GetLastError() to process error returns */

acfssettag

Purpose

Sets the tag name on an Oracle ACFS file. For additional information, refer to "acfsutil tag set".

Syntax

sb8 acfssettag(const oratext *path, const oratext *tagname, oratext *value, 
               size_t size, ub4 flags);

Table 17-7 contains the options available with the acfssettag command.

Table 17-7 Options for the acfssettag command

Option Description

path

Specifies a pointer to a file or directory path name.

tagname

Specifies a pointer to a NULL-terminated Oracle ACFS tag name in the format of a valid tag name for regular files and directories.

value

Specifies the memory buffer to set the Oracle ACFS tag value.

size

Specifies the byte size of the Oracle ACFS tag value.

flags

Reserved for future use. Must be set to 0.

Description

The acfssettag library call sets a tag name on an Oracle ACFS file. The return value is ACFS_TAG_SUCCESS or ACFS_TAG_FAIL. For information about operating system-specific extended error information values that may be obtained when an ACFS_TAG_FAIL is returned, refer to "Oracle ACFS Tagging Error Values".

Because Oracle ACFS tag names currently use a fixed value string of 0 (the number zero character with a byte length of one) the value is the same for all Oracle ACFS tag name entries.

Examples

Example 17-7 is an example of the use of the acfssettag function call.

Example 17-7 Setting file tags

sb8 rc;
size_t size;
const oratext *value ;
const oratext *path= "/mnt/dir1/dir2/file2";
const oratext *tagname = "patch_set_11_1";
value = "0"; /* zero */
size = 1; (byte)
rc = acfssettag (path, tagname, (oratext *)value, size, 0);
If (rc == ACFS_TAG_FAIL)
  /* check errno and GetLastError() to process error returns */

Oracle ACFS Diagnostic Commands

This topic provides a summary of the Oracle ACFS command-line utilities for diagnostic purposes.

Oracle ACFS provides various acfsutil command-line utilities for diagnostic purposes.

Note:

Run the diagnostic commands only when Oracle Support requests diagnostic data for analysis.

The following table lists the Oracle ACFS utilities with brief descriptions.

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

Table 17-8 Summary of Oracle ACFS diagnostic commands

Command Description

acfsdbg

Debugs an Oracle ACFS file system.

acfsutil blog

Writes text to a blog file.

acfsutil dumpstate

Collects internal Oracle ACFS state information.

acfsutil log

Retrieves memory diagnostic log files and manages debug settings.

acfsutil meta

Copies metadata from an Oracle ACFS file system into a separate output file.

acfsutil plogconfig

Manages Oracle ACFS persistent logging configuration settings.

acfsdbg

Purpose

Debugs an Oracle ACFS file system.

Syntax and Description

acfsdbg [-r] [-l] [-x] volume_device
acfsdbg -h

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

Table 17-9 contains the options available with the acfsdbg command.

Table 17-9 Options for the acfsdbg command

Option Description

-h

Prints out the usage message which displays the various options that are available when invoking the acfsdbg command, then exits.

-r

Operates in read-only mode. No data is modified on the file system and all write commands are disabled. If the device is mounted anywhere, acfsdbg may not display the latest data because some data is cached by the file system mounts.

-l

Processes kernel log files. The default is to not process the log files.

—x file_name

Specified for accelerator data collected by acfsutil meta. Only used for this type of data.

volume_device

Specifies the device name of the volume.

acfsdbg is an extension to fsck and acfschkdsk, and is an interactive program that views and modifies on disk structures of the file system.

Note:

The acfsdbg command is intended for experienced development and support engineers to examine on disk structures to diagnose problems. Use with caution.

When acfsdbg is started, it displays a command prompt. At the command prompt, you can enter the subcommands listed in Table 17-10.

You can also use acfsdbg for scripts by echoing acfsdbg subcommands with a shell pipe to the acfsdbg binary.

By default the file system is not modified when running the tool. If the -l option is used, the file system metadata in the transaction logs is applied before the interactive disk block dump session. The volume device must specify a volume with a dismounted Oracle ACFS file system. If the volume device has a mounted Oracle ACFS file system, acfsdbg displays an error message and exits.

You must be the administrator or a member of the Oracle ASM administrator group to run acfsdbg.

Subcommands

Table 17-10 lists the subcommands of acfsdbg.

Table 17-10 Subcommands for acfsdbg

Option Description Syntax

calculate

Calculates simple arithmetic expressions

Valid operators: + - * / % & | ^ ~ << >>

White space starts a new expression

0-1 represents a negative 1

calculate [-v] expr […]

  • -v Verbose mode
  • expr Simple 2+2 expression

cksum

Generates and replaces checksum in header

Header offset can be an expression as used by the calculate subcommand

White space starts a new header offset

Command is disabled in read-only mode

cksum [-C | -CE] header_offset […]

  • -C Regenerate for normal structure checksum
  • -CE Re-generate for Extent structure checksum
  • header_offset Offset of the on disk structure header. The value can be an expression as used by the calculate subcommand

close

Closes the open handle to the device

close

echo

Echoes text on command line to stdout

echo

fenum

Displays the specified File Entry TAble (FETA) entry

fenum [-f | -e | -d] FETA_entry_number

  • -f Displays all on disk structures related to this structure
  • -e Displays all on disk extent information related to this structure
  • -d Casts the structure as a directory and displays its contents
  • FETA_entry_number The File Entry Table number used to identify a file on the file system

help

Displays help message

help

offset

Displays structure at disk offset

offset [-c cast] [-f | -d] disk_offset

  • -f Displays all on disk structures related to this structure
  • -d Casts the structure as a directory and displays its contents
  • disk_offset Disk offset to display. The value can be an expression as used by the calculate subcommand

open

Opens a handle to a device. The default is the volume device name entered on the command line

open [volume_device]

primary

Sets the context of commands to the primary file system

primary

prompt

Sets the prompt to the specified string

prompt "prompt_string"

quit

Exits the acfsdbg debugger command

quit

read

Reads value from offset

The default size to read in is 8 bytes

The default count to read is 1

read [-1 | -2 | -4 | -8 | -s] [count] offset

  • -1 Read byte value
  • -2 Read 2 byte (short) value
  • -4 Read 4 byte (int) value
  • -8 Read 8 byte (long) value
  • -s Read null- terminated string
  • count Number of values to read. If not specified, the default is 1
  • offset Disk offset to read. The value can be an expression as used by the calculate subcommand

snapshot

Sets the context of commands to the specified snapshot

snapshot snapshot_name

write

Writes hexadecimal, octal, or decimal values at the disk offset, estimating how many bytes to write based on value size or number of digits in leading 0 hexadecimal values

The disk offset can be an expression used by the calculate subcommand

Numeric values can also be an expression as used by the calculate subcommand

This command is disabled in read-only mode

write [-1 | -2 | -4 | -8 | -c | -s] [-C | -CE] offset value

  • -1 Write byte value
  • -2 Write 2 byte (short) value
  • -4 Write 4 byte (int) value
  • -8 Write 8 byte (long) value
  • -c Write text (no null termination). Enclose string in single-quotes (')
  • -s Write null-terminated string. Enclose string in quotes (")
  • -C Regenerate normal structure checksum
  • -CE Regenerate extent structure checksum
  • offset Disk offset to write. The value can be an expression used by the calculate subcommand
  • value The value to write. If numeric, the value can be an expression as used by the calculate subcommand

Examples

Example 17-8 shows the use of the acfsdbg subcommand.

Example 17-8 Using the acfsdbg command

$ /sbin/acfsdbg /dev/asm/voume1-123
acfsdbg: version                   = 11.2.0.3.0
Oracle ASM Cluster File System (ACFS) On-Disk Structure Version: 39.0
The ACFS volume was created at  Mon Mar  2 14:57:45 2011
acfsdbg> 

acfsbdg> calculate 60*1024
    61,440
    61440
    61440
    0xf000
    0170000
    1111:0000:0000:0000

acfsdbg> prompt "acfsdbg test>"
acfsdbg test>

echo "offset 64*1024" | acfsdbg /dev/asm/volume1-123

acfsutil blog

Purpose

Writes text to the blog file.

Syntax and Description

acfsutil [-h] blog

acfsutil blog {-t text | -u} mount_point

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

The following table contains the options available with the acfsutil blog command.

Table 17-11 Options for the acfsutil blog command

Option Description

-t text

Writes text to the blog file at the specified mount point.

-u

Updates blog debug levels from dbg file.

mount_point

Specifies the mount point.

The acfsutil blog command enables you to write text to a blog file.

.

Examples

The following example illustrates how to run the acfsutil blog command. Running acfsutil blog with the —h option displays help.

Example 17-9 Using acfsutil blog

$ /sbin/acfsutil -h

$ /sbin/acfsutil -t "this is a blog test" blog my_mount_point

$ /sbin/acfsutil -u blog my_mount_point

acfsutil dumpstate

Purpose

Collects internal Oracle ACFS state information for diagnosis by Oracle support.

Syntax and Description

acfsutil [-h] dumpstate 
acfsutil dumpstate acfs_path

acfsutil -h dumpstate displays help text and exits.

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

The following table contains the options available with the acfsutil dumpstate command.

Table 17-12 Options for the acfsutil dumpstate command

Option Description

acfs_path

Specifies the directory to a file in an Oracle ACFS file system.

The acfsutil dumpstate command collects internal Oracle ACFS state information for a specified file and its corresponding file system. The state information is written to a binary incident file in a logging directory.

Note:

Run the acfsutil dumpstate command only when Oracle Support requests diagnostic and debugging data for analysis.

Examples

The following example shows the use of the acfsutil dumpstate command.

Example 17-10 Using the acfsutil dumpstate command

$ /sbin/acfsutil dumpstate /acfsmounts/acfs1/myfile

acfsutil log

Purpose

Retrieves memory diagnostic log files and manages debug settings.

Syntax and Description

acfsutil [-h] log

acfsutil log [-f filename] [-s] [-r n{K|M|G|T|P}] [-p {avd|ofs|oks}] [-l debuglevel] 
         [-n consolelevel] [-o wait_time] [-q] [-c debugcontext] [-T file_type] 
         [-m mount_point] [-a] [-C] [-t]

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

The following table contains the options available with the acfsutil log command.

Table 17-13 Options for the acfsutil log command

Option Description

-f filename

Write the in-memory log to the specified file. The default file is oks.log in the current directory.

-s

Shows the size of the in-memory log file.

-r n{K|M|G|T|P}

Sets the size of the in-memory log file.

-p {avd|ofs|oks}

Specifies the product for setting the level or querying settings. The is default all products: Oracle ADVM (avd), Oracle ACFS (ofs), and Oracle Kernel Services (oks)

-l debuglevel

Sets the in-memory debug level. The default debug level is 2. Valid values are 0-6.

-n consolelevel

Sets the debug level for persistent logging . Other persistent log configuration settings are managed by the acfsutil plogconfig command.

-o wait_time

Sets the log size, the debug level, and the product values on all nodes; waits for the number of seconds specified by wait_time; dumps in the memory log on all nodes; and then resets the debug level and the log size.

-q

Queries the debug settings for a specified product.

For example: acfsutil log —p avd —q

-c debugcontext

Sets the debug context, internal only.

-T file_type

Sets the debug file type, internal only.

—m mount_point

Specifies to debug only the file system at the specified mount point.

-a

Resets the debug logging to log for all file systems.

-C

Dumps a memory log on all cluster nodes, and also can be added to -t option.

-t

Dumps all Hang Manager thread information to in-memory and persistent logs.

The acfsutil log command enables you to manage memory diagnostic log files. With none of the options specified, the acfsutil log command retrieves and writes the ./oks.log memory log by default.

The -o option performs the following:

  1. Sets the log size to 500M , the log level to 5, and the product to ofs (acfs) for the in-memory log on all nodes

  2. Displays an informational message, such as Blocking for 180 seconds, reproduce problem now

  3. After waiting for the specified number of seconds, then displays Dumping log on all nodes

  4. Initiates a clusterwide dump of logs

  5. Resets the log level to 2 and resets the log size to the default

The -o option can be combined with the -p, -l, and -r options if the default product, debug level, or log size settings should be changed.

You must be the root user or an Oracle ASM administrator user to run this command.

Examples

The following example illustrates how to run the acfsutil log command to display help.

Example 17-11 Using acfsutil log

$ /sbin/acfsutil -h log 

acfsutil meta

Purpose

Copies metadata from an Oracle ACFS file system into a separate output file.

Syntax and Description

acfsutil meta -h
acfsutil meta [-v] [-q] [-l log_file_path] [-o acfs_extent_offsets] {-f output_file} [-a <device>]  volume_device

acfsutil meta -h displays help text and exits.

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

Table 17-14 contains the options available with the acfsutil meta command.

Table 17-14 Options for the acfsutil meta command

Option Description

—v

Specifies verbose mode to generate additional diagnostic messages.

—q

Invokes the metadata collector in quick mode.

-l log_file_path

Specifies the path to the log file. If not specified, the log file is generated in the current directory with a default name of acfs.meta.log.

—o acfs_extent_offsets

Specifies a list of comma separated file offsets from which the meta collector additionally copies data.

—f output_file

Specifies the path name of the output file into which the metadata is copied.

—a device

Specifies the location of any associated accelerator device, to be used if the file system is unmountable.

volume_device

Specifies a volume device name of the file system which is to be copied.

The acfsutil meta command operates as a metadata collector to partially copy an Oracle ACFS file system into a separate specified output file. The metadata collector reads the contents of the file system specified by the volume device name of an Oracle ACFS file system. This input file system is searched for Oracle ACFS metadata and then all metadata found is written into the specified output file. The generated output file can be used for further diagnostics and analysis, without impact to the original file system at the customer site.

To obtain the best copy of the file system with acfsutil meta, unmount the file system before running acfsutil meta. If it is not possible to unmount the file system, avoid modifying the contents or performing a volume resizing operation while acfsutil meta is running.

If the original file system is very large, then the output file can also be very large. The output file should be placed on a file system that supports sparse files because this placement can reduce the size of the file. When copying the output file, use a utility that supports sparse files. Compress the output file when possible to reduce storage space and transmission time.

If the file system has an accelerator device associated with it, acfsutil meta also copies the accelerator device data to a second output file. The second file uses the file name from the -f option with an appended .acc extension. For example, if you specify acfsutil meta -f /tmp/mymetafile volume1-123, the meta collector places a copy of volume1-123 in /tmp/mymetafile, and the copy of its accelerator device in the /tmp/mymetafile.acc file. This operation occurs automatically.

In most circumstances, acfsutil meta automatically copies the accelerator device to the second file. However, if you have think that the meta collector is not able to find the accelerator device on its own, you can specify the name on the command line with the -a option. For example, this situation could occur if the file system is corrupt. Note that using the -a option overrides how the meta collector operates automatically, so -a should be used carefully.

The output file should not be placed on the Oracle ACFS device that is specified as the input device because the metadata command might process the output file also. The output file should be placed on a file system that can support an output file which is the size of the Oracle ACFS input volume device.

The -q flag should be used with caution. When -q is specified, the meta collector does not scan and copy the entire input file system. Instead, it only scans and copies a predetermined number of bytes and certain data structures which are considered important. The primary use for the -q flag is for situations where there is not sufficient time to run the full version of the metadata collector. The -q flag should not be used unless it is recommended by the support personnel investigating the problem.

The acfsutil meta output file can be read by the acfsutil fsck command in most cases. However, the Oracle ACFS specific acfsutil fsck command on some OS platforms might not access the output file correctly or might not work with a specified flag. You can use a slightly modified fsck command form in these cases. For example:

  • On Linux, run the command in this format if you are using the —x flag:

    /sbin/fsck.acfs -x accelerator_meta_file meta_output_file
  • On AIX, run the command in this format:

    /sbin/helpers/acfs/fsck meta_output_file

Examples

Example 17-12 shows the use of the acfsutil meta command.

Example 17-12 Using the acfsutil meta command

$ /sbin/acfsutil meta -f /acfsmounts/critical_apps/meta_output_file /dev/asm/volume1-123

acfsutil plogconfig

Purpose

Manages Oracle ACFS persistent logging configuration settings.

Syntax and Description

acfsutil plogconfig [-h] [-d persistent_log_directory] [-t] [-q ] [-i seconds] 
                    [-s buffer_size] [-l low_water_percent] [-u high_water_percent] 
                    [-m max_logfile_size] [-n max_logfile_number]

acfsutil -h plogconfig displays help and exits.

For information about running Oracle ACFS acfsutil commands, refer to About Using Oracle ACFS Command-Line Tools.

The following table contains the options available with the acfsutil plogconfig command.

Table 17-15 Options for the acfsutil plogconfig command

Option Description

-d persistent_log_directory

Specifies an alternative logging directory. If not specified, the default directory is $ORACLE_BASE/crsdata/hostname/acfs.

-t

Terminates logging.

-q

Queries for and then displays the persistent logging configuration settings.

-i seconds

Specifies the number of seconds for the interval timer.

-s buffer_size

Sets the log buffer size in kilobytes.

-l low_water_pecent

Sets the file write trigger as a percentage.

-u high_water_pecent

Sets the file write throttle as a percentage.

-m max_logfile_size

Sets the maximum log file size in megabytes.

-n max_logfile_number

Sets the maximum number of log files.

The acfsutil plogconfig command provides a diagnostic tool to manage configuration settings for persistent logging.

All command arguments are optional, but at least one argument must be specified.

Note:

Run the acfsutil plogconfig command only when Oracle Support requests configuration of persistent logging settings.

You must be the root user or an Oracle ASM administrator user to run this command.

Examples

The following example illustrates the use of the acfsutil plogconfig command to display the current configuration settings.

Example 17-13 Using the Oracle ACFS acfsutil plogconfig command

# /sbin/acfsutil plogconfig -q

Log Directory Name : /oracle/crsdata/my_host/acfs 
Buffer Size (KB) : 64
Low Water Level (percent) : 50
High Water Level (percent) : 75
Timer Interval (Seconds) : 5
Maximum Number of Log Files : 10
Maximum Log File Size (MB) : 100

Understanding Oracle ACFS I/O Failure Console Messages

Oracle ACFS logs information for I/O failures in the operating-specific system event log.

A console message has the following format:

[Oracle ACFS]: I/O failure (error_code) with device device_name during a operation_name op_type.
file_entry_num Starting offset: offset. Length of data transfer: io_length bytes.
Impact: acfs_type   Object: object_type   Oper.Context: operation_context 
Snapshot?: yes_or_no AcfsObjectID: acfs_object_id . Internal ACFS Location: code_location.

The italicized variables in the console message syntax correspond to the following:

  • I/O failure

    The operating system-specific error code, in Hex, seen by Oracle ACFS for a failed I/O. This may indicate a hardware problem, or it might indicate a failure to initiate the I/O for some other reason.

  • Device

    The device involved, usually the ADVM device file, but under some circumstances it might be a string indicating the device minor number

  • Operation name

    The kind of operation involved:

    user data, metadata, or paging

  • Operation type

    The type of operation involved:

    synch read, synch write, asynch read, or asynch write

  • File entry number

    The Oracle ACFS File entry number of the file system object involved, as a decimal number. The acfsutil info fileid tool finds the corresponding file name.

  • Offset

    The disk offset of the I/O, as a decimal number.

  • Length of I/O

    The length of the I/O in bytes, as decimal number.

  • File system object impacted

    An indication that the file system object involved is either node-local, or is a resource accessed clusterwide. For example:

    Node or Cluster

  • Type of object impacted

    A string indicating the kind of file system object involved, when possible. For example:

    Unknown, User Dir., User Symlink, User File, Sys.Dir, Sys.File, or MetaData

    • Sys.Dir.

      Oracle ACFS-administered directory within the visible namespace

    • sys.File

      Oracle ACFS-administered file within the visible namespace

    • MetaData

      Oracle ACFS-administered resources outside of the visible namespace

  • Operational context

    A higher-level view of what code context was issuing the I/O. This is for use by Oracle Support Services. For example:

    Unknown, Read, Write, Grow, Shrink, Commit, or Recovery

  • Snapshot

    An indication of whether, if possible to determine, the data involved was from a Snapshot. For example:

    Yes, No, or ?

  • Object type of the file system

    An internal identifier for the type of file system object. For use by Oracle Support Services.

  • Location of the code

    An internal identifier of the code location issuing this message. For use by Oracle Support Services.

The following is an example from /var/log/messages in a Linux environment:

[Oracle ACFS]: I/O failure (0xc0000001) with device /dev/sdb during a metadata synch write .
Fenum Unknown. Starting offset: 67113984. Length of data transfer: 2560 bytes.
Impact: Node   Object: MetaData   Oper.Context: Write
Snapshot?: ?  AcfsObjectID: 8  . Internal ACFS Location: 5 .