NAME

stager.cmd - Defines Oracle HSM stager directives

SYNOPSIS

∕etc∕opt∕SUNWsamfs∕stager.cmd

AVAILABILITY

SUNWsamfs

DESCRIPTION

Directives for controlling the Oracle HSM stager are read from ∕etc∕opt∕SUNWsamfs∕stager.cmd.

Staging with tape drive data protection (DIV) is enabled in the defaults.conf file by setting the div parameter.

In the stager.cmd file, each directive must appear on its own line. Each directive has the following format:

keyword = value

Comment lines can appear in the stager.cmd file. A pound sign (#) in column 1 indicates a comment line.

The stager.cmd file accepts the following directives:

delay_time = time

Sets the amount of time to delay when attempting to stage files from unavailable media returning EAGAIN on a read. Currently this is used for cloud (7) media when staging released objects from archive containers. The minimum value is 30 seconds and the maximum is 4 hours. The default is 10 minutes. Valid time abbreviations are 's', 'm', and 'h'.

directio = on|off

Set the file reading method for staging. The directive on will set direct I∕O for all staging if file size is equal to or greater than dio_min_size. off will cause paged I∕O to be used. The default is on.

NOTE: Staging on a shared QFS file system always uses direct I∕O.

dio_min_size = n

If the file size is n megabytes, the stager will use paged I∕O for non-shared QFS file systems. The default is 8 megabytes. If directio = off all stage io is paged.

NOTE: dio_min_size is ignored for shared QFS file systems which always use direct I∕O.

distio = on|off

Set whether the stager uses distributed tape IO when enabled in defaults.conf (4). This provides a mechanism to disable distributed tape IO for staging but still allow it for archiving. The default is on.

drives = library count

Sets the number of drives to use for staging on media library library to a number specified by count. The default value is the actual number of drives in library.

The library specified must be the family set name of a media library as defined in the mcf file. If this directive is specified, the stager uses only count number of drives in the media library to stage archive copies. This directive prevents the stager from using all drives in a media library and possibly interfering with archiving.

For example, the following directive specifies that 3 drives should be used for staging in an ADIC∕Grau media library.

drives = gr50 3

bufsize = media buffer_size [ lock ]

Sets the stage buffer size for a specific media type.

For media, specify a media type from the mcf (4) man page.

For buffer_size, specify an integer value in the range 2 ≤ buffer_size ≤ 8192. The default is 16. The buffer_size specified is multiplied by the default block size for media. For more information on default block sizes, see the dev_blksize description on the defaults.conf (4) man page.

If lock is specified, the stager locks the stage buffer in memory. If the stage buffer is locked, system CPU time can be reduced.

logfile = filename [event]

Sets the name of the stager log file to filename, specified as an absolute pathname. By default, no log file is written. event is start, finish, cancel, error, or all. The default is finish, cancel, and error.

The stager log file contains a line for each file staged. The line contains the event type, date, time, media, VSN, inode generation number of the file, position and offset of where the file is stored, name of the file, copy number, user id, group id, requestor's user id, equipment number of the drive upon which the file was staged, and the type of stage, 'V' for data verify and '-' for others.

maxactive = number

Sets the maximum number of stage requests that can be active at one time in the stager to an integer number. The minimum number is 1. The default number is based on memory size, 5000 per gigabyte. The maximum number is 2000000.

The number of outstanding stage requests has a direct impact on incore inode usage, since each request requires an incore inode for the duration of the stage. Sites may wish to increase the default number of incore inodes if they greatly increase the maximum number of stage requests. This can be done by setting ninodes in the ∕etc∕system file, as shown in the following example.

set samfs:ninodes=100000

For more information on ninodes, see the StorageTek QFS File System Configuration and Administration Guide.

maxretries = number

Sets the maximum number of stage retries attempted per archive copy when certain errors are encountered to an integer number. The minimum number is 0. The default number is 3. The maximum number is 20.

cksum_v1_legacy = on|off

Set the version 1 checksum behavior for staging. The value on will allow the same behavior as in previous systems. The value off will cause mismatching checksums due to moving a file with a long name to be accepted. The default is off.

rearch_method = separate|mix|off

Set the schedule method for staging files for rearchive. The directive separate will separate request from the archiver for rearchive from other requests, and assign the lowest priority. The directive mix will separate request from the archiver for rearchive from other requests, and assign the lowest priority. But, if there are requests not from the archiver and that request's archive copy is on the same VSN, request will not be separated. The directive off will not separate request from the archiver. The default is off. NOTE: rearch_offline_behind directive in archiver.cmd (4) controls scheduling rearchive offline files.

copysel = n1:n2:n3:n4

Sets the copy selection sequence for staging. n? must be a range of 1 = n? = 4. By default, 1:2:3:4 is defined, so copy number 1, 2, 3 then 4 is selected for staging if stage is not initiated by stage (1) and copy number is not specified by -c option.

Four copies, n1 to n4, must be defined, even if there are less than four copies available.

fs = file_system_family_set_name

Specifies that the subsequent directives apply to the indicated file_system_family_set_name only until stream definition is met. File system specific directives override general directives.

NOTE: Currently, only copysel definition can be defined for the specific file system.

STREAM DEFINITIONS SECTION

The streams and endstreams directives delimit this section of the stager.cmd file.

Each line begins with the media type followed by the definitions. The syntax for this line is as follows:

media definitions

where:

media

The media type. Currently, only 'dk' is supported.

definitions | -maxsize size

Set the maximum size of the stream to size. size may be specified with the suffixes 'b', 'k', 'M', 'G', and 'T', for bytes, kilobytes, megabytes, gigabytes, and terabytes. The default unit size is bytes. The default value is 1G bytes. Files to be staged from the same stream will be added to the same stream. If size of the stream hit the size, new stream will be created for the VSN.

-maxcount count

Set the maximum file count to count for the each stream. The default value is 0. Files to be staged from the same VSN will be added to the same stream. If count of the file hit the count, new stream will be created for the VSN.

If more than one of -maxsize or -maxcount are specified, the first condition encountered creates the new stream for VSN.

EXAMPLES

The following is an example ∕etc∕opt∕SUNWsamfs∕stager.cmd file:

logfile = ∕var∕opt∕SUNWsamfs∕log∕stager
drives= hp30 1
copysel = 4:3:2:1
fs = samfs1
copysel = 3:1:4:2
streams
dk -maxsize 2G -maxcount 10000
endstreams

The results of the stager's operations are found in ∕var∕opt∕SUNWsamfs∕log∕stager. For the media library specified as hp30, the stager is allowed to use only 1 drive for staging files. The stager selects copy number 4, 3, 2 then 1 for staging files by default. The stager selects copy number 3, 1, 4 then 2 for staging files for the file system samfs1. The size of stream is limited to 2G bytes, and the maiximum file count for the each stream is limited to 10000 for the media type dk.

FILES

The following files are used by the stager:

∕etc∕opt∕SUNWsamfs∕stager.cmd: Stager command file.