3
Creating Raw Devices

This chapter describes how to create the raw devices required by Oracle Parallel Server data files, control files and redo log files. These steps assume you have installed the vendor-supplied Operating System Dependent layer and performed diagnostics on the clusterware, as described in your vendor documentation.

Specific topics discussed are:

• Raw Devices Overview
• Disk Definition
• Creating Raw Devices for Automatic or Manual Database Creation
• Creating Raw Devices for the Oracle Database Configuration Assistant
• Creating Raw Devices for Manual Database Creation
• Creating Raw Devices for Manual Database Creation with a Current Configuration

 

 

 

See Also: This chapter is a supplement to the following guide: Oracle8i Parallel Server Setup and Configuration Guide, Chapter 2, "Pre-Installation".

Raw Devices Overview

As Windows NT does not support a proper distributed file system, Oracle bypasses it by using raw devices. This allows nodes running different instances to access shared disks. Data files, redo log files, and control files are stored on the raw devices. The shared disks are then a collection of unformatted raw devices.

Raw devices are created on a disk that does not have a primary partition and has only one extended partition. Raw devices are created prior to installation and creating a database.
 

Note: You need to create raw devices if you are creating a database manually, or using the Oracle Database Configuration Assistant to create the files for the database. However, if you are using the Oracle Database Configuration Assistant, a precise number of raw devices must be set up.

Raw Devices

A raw device is a portion of a physical disk that Oracle8i on Windows NT uses for its database files. Raw devices are not like regular file management systems. The information they store cannot be identified or accessed by users. The use of raw devices may improve disk I/O performance by 5% to 10% when compared with disk I/O to a partition with a file system on it.

A raw device is created when an extended partition is created and logical partitions are assigned to it without applying any formatting. The Windows NT Disk Administrator application allows you to create an extended partition on a physical drive.

Primary Partitions

A primary partition is one into which you can install the files needed to load an operating system. It is usually formatted for a particular file system and is assigned a drive letter. There can be, at most, four primary partitions on a physical drive.

Extended Partitions

An extended partition points to raw space on the disk that can be assigned multiple logical partitions for the database files. An extended partition avoids the four-partition limit by allowing you to define large numbers of logical partitions to accommodate applications using Oracle8i on Windows NT. Logical partitions can then be given symbolic link names to free up drive letters. This makes Oracle Parallel Server on Windows NT more scalable.

The Disk Administrator window below shows two disks. Disk 1 has an extended partition:

The following table describes the partitions on disk 0 and disk 1:

This disk...	Contains...
Disk 0	Two primary partitions
Disk 1	An extended partition with nineteen logical partitions and 134 MB of free space (this disk device includes six physical disk drives)

The data files, control files and redo log files must be created on the logical partitions.
 

Note: You can tell whether space is unpartitioned free space or free space within an extended partitions by the direction of the diagonal lines. Lines for free space within an extended partition display from top left to the bottom (\\), and lines for unpartitioned free space display from top right to the bottom (//).

Disk Definition

Windows NT uses the following naming convention to define each disk drive it finds at startup, where m is the number of the physical drive, and n is a partition number (logical partition number) as shown in the Disk Administrator window:

\Device\Harddiskm\Partitionn

For example, the first drive on a system (normally the C: drive) has the following name:

\Device\Harddisk1\Partition0

The first logical drive (E:) defined on the second physical drive has the following name:

\Device\Harddisk2\Partition1

 

Note: When the nodes are rebooted, the hard disk and partition names can change, and symbolic link names mapped to a different partition. However, the physical disk remains the same. The Oracle Object Link Manager, described in this chapter, tracks and updates the symbolic links, so that the links are mapped correctly after rebooting.

Physical Disk

A physical disk represents the entire disk. It points to \Device\Harddiskx\Partition0. Windows NT automatically creates a symbolic link name of \\.\PhysicalDriveX, where X is the number corresponding to your hard disk drive number in the Disk Administrator. The X matches the X in \Device\HarddiskX\Partition0.

\\.\PhysicalDriveX is automatically defined by Windows NT for every hard disk in the machine. For example, a machine with three hard disks will have the following names defined by Windows NT:

\\.\PhysicalDrive0

\\.\PhysicalDrive1

\\.\PhysicalDrive2

Internally, these names expand to:

\\.\PhysicalDrive0 = \Device\Harddisk0\Partition0

\\.\PhysicalDrive1 =\Device\Harddisk1\Partition0

\\.\PhysicalDrive2 =\Device\Harddisk2\Partition0

Partition0 is special in that it represents the entire physical disk regardless of any partitioning scheme on that disk. On all disks recognized by Windows NT, the Disk Administrator writes a signature on the first block of all disks. To avoid overwriting that block, Oracle skips the first block of a physical raw partition which is used for an Oracle data file.

Physical Partition Naming Conventions for Oracle Parallel Server

Oracle Parallel Server adopts a special naming convention to distinguish physical partitions within an extended raw partition from files on a file system. The first 17 characters of the name must be:

\\.\PhysicalDrive

Logical Partition

A logical partition is a partition created by the Disk Administrator that points to a drive other than \Device\Harddiskx\Partition0. Logical partitions are initially assigned names with drive letters (\\.\drive_letter:) and typically re-assigned symbolic link names (\\.\symbolic link name).

For example, \\.\D: may be assigned a symbolic link name of \\.\ops_sys1. Regardless of whether a drive letter or symbolic link name is used, logical partitions are defined to represent a specific partition in a disk rather than the entire disk. Internally, these names may expand to:

\\.\D:= \Device\Harddisk2\Partition1

\\.\op_system1= \Device\Harddisk3\Partition2
 

Note: Oracle does not skip the first block of a logical raw partition used for an Oracle data file.

Physical Disk and Logical Partition Considerations

Please consider the following when deciding which raw partition to use:

• Physical disks are automatically defined by Windows NT to represent the entire disk, and should never be defined by the user.
• Logical partitions need to be defined by the user to represent a specific partition in a disk. These partitions should be logical partitions or drives contained in an extended partition. They should never be defined as Partition0.
• Using an entire disk (Partition 0) for an Oracle data file and using a partition which occupies the entire disk for an Oracle data file is not the same thing. Even when a partition occupies the entire disk, there is still a small space on the disk that is not part of the partition.
• If you are using an entire disk for an Oracle data file (Partition 0), use the pre-defined physical raw names which Windows NT provides.
• Use a logical partition if you are using a specific partition and it occupies the entire disk.
• If using a specific partition created with the Disk Administrator, define and use a symbolic link name rather than a logical partition number (even if it occupies the entire disk).

 

 

Frequently Asked Questions

Question: What is the impact if I have created logical partitions, but defined physical disk convention names for them. For example:


\\.\PhysicalDrivesys1 = \Device\Harddisk2\Partition1


\\.\PhysicalDriveusr1 =\Device\Harddisk3\Partition1


Answer: An Oracle database will handle the data file using the physical disk convention, even though it really is a logical partition. This will not cause any data corruption or loss, as long as you continue using the physical disk naming conventions. Oracle Corporation recommends you convert to the logical partition at your earliest convenience. See "Compatibility Issues".


Question: What is the impact if I have created logical names representing Partition0. For example:


\\.\op_system1 = \Device\Harddisk1\Partition0


Answer: This will pose severe problems, as the Disk Administrator typically writes a signature into the first block of every disk, and consequently may overwrite a portion of the data file header.
 

Note: This may also cause data loss. Never use Partition0 with the logical partition convention. See "Compatibility Issues" for information on rebuilding your Oracle database with the proper conventions.

Question: How do I transfer the contents of any raw partition to a standard file system for backup purposes?


Answer: Use the Oracle utility OCOPY to copy data to or from a raw partition for both physical and logical raw conventions. See "Compatibility Issues" for further information.

Compatibility Issues

The physical and logical partition conventions are not compatible with one another due to the extra block that is skipped for physical raw conventions. This also means you cannot simply do an OCOPY from a physical disk to a logical partition, as the contents of these partitions are incompatible.

To convert from a physical convention to a logical convention, you must:

1. Perform a full database export to a (local) file system.
2. Create logical partitions and define logical names for these partitions.
3. Re-create the database using the new logical partitions.
4. Perform the full database import to the newly created database.

 

 

If your database installation uses physical disk conventions with logical partitions, Oracle Corporation recommends converting to the logical partition conventions at your earliest convenience using the steps above.

Creating Raw Devices for Automatic or Manual Database Creation

The following sections describe how to create the raw devices for three types of configurations:

• Creating Raw Devices for the Oracle Database Configuration Assistant
• Creating Raw Devices for Manual Database Creation
• Creating Raw Devices for Manual Database Creation with a Current Configuration

 

 

Creating Raw Devices for the Oracle Database Configuration Assistant

Using the Oracle Database Configuration Assistant on a clean machine is the preferred method to create a database for Oracle Parallel Server.

To create the raw devices, perform the following steps:

• Step 1: Install Oracle Parallel Server Raw Devices Management Utilities
• Step 2: Create an Extended Partition
• Step 3: Create Logical Partitions
• Step 4: Assign Symbolic Link Names

 

 

 

Note: The Oracle Database Configuration Assistant requires a precise number of raw devices for the database files. See Oracle8i Parallel Server Setup and Configuration Guide, page 2-5, for the number of raw devices, the sizes of the raw partitions, and the symbolic link names necessary for Oracle Database Configuration Assistant files.

Step 1: Install Oracle Parallel Server Raw Devices Management Utilities

To install the Oracle Parallel Server raw devices management utilities, perform the following tasks on one node of the cluster:

1. Create a temporary directory.
2. Insert the Oracle8i Enterprise Edition CD-ROM.
3. Copy the contents of the \OPS_PREINSTALL directory to the temporary directory you created.

 

 

 

Note: If you plan to assign symbolic link names after installing Oracle8i Enterprise Edition and creating a database using the Oracle Database Configuration Assistant, do not perform the following step. The ORACLEOBJSERVICE is automatically installed.

4. Install ORACLEOBJSERVICE on all nodes of the cluster by entering the following command from the temporary directory you created:

C:\> ORACLEOBJSERVICE /INSTALL

This installs the ORACLEOBJSERVICE as an automatic startup type whenever you reboot. This service monitors symbolic link changes and updates all nodes when changes occur on one node.

To remove ORACLEOBJSERVICE, use the following command:

C:\> ORACLEOBJSERVICE /REMOVE

For more information about the install and remove options, use the following command:

C:\> ORACLEOBJSERVICE /HELP

Step 2: Create an Extended Partition

Extended partitions point to raw space on disk drives. Multiple logical partitions are created in these extended partitions.

Only one extended partition can be created per disk. You can use the free space in the extended partition to create multiple logical partitions or use all or part of it when creating volume sets or other kinds of volumes for fault-tolerance purposes.

To create an extended partition, perform the following tasks:

1. Shut down all nodes except one of the nodes.
2. On the node that is up, choose Start > Programs > Administrative Tools > Disk Administrator.




The Disk Administrator window appears:


Note the lines display diagonally from top right to the bottom left, indicating unpartitioned devices.

3. Select an area of free space in an extended partition on a disk that is on the shared disk subsystem by clicking the mouse.




Oracle Corporation recommends you use the entire disk.

4. Choose Partition > Create Extended.




The Disk Administrator displays the minimum and maximum sizes for the extended partition:


5. Use the default maximum size, then click OK.


 

Note: Changes you have made are not saved until you choose Commit Changes Now from the Partition menu or quit the Disk Administrator.

The extended partition is created.


Note the lines now display diagonally from top left to bottom right, indicating the partition is an extended partition.

Step 3: Create Logical Partitions

Logical partitions are created on one node of the cluster. To create logical partitions in an extended partition:
 

Note: Oracle Corporation recommends you do not create more than 120 logical partitions in an extended partition.

1. On one of the nodes, select an area of free space in an extended partition by clicking the mouse on it.
2. Choose Partition > Create.




The Disk Administrator window displays the minimum and maximum sizes for the logical partition.

3. Enter the size of the logical partition, then click OK.

 

 

 

Note: You can modify file sizes later, but not the raw devices. File sizes cannot expand the size of the raw device.

4. Repeat Steps 1-3 until you have the required number of logical partitions.
5. Choose Partition > Commit Changes Now.




A confirmation dialog appears, informing you changes have been made to the disk.

6. Click Yes to acknowledge the message.




A dialog box appears, informing you the disks have been updated successfully.

7. Click OK.
8. Choose Partition > Close.

 

 

To make the changes visible, on all nodes of the cluster, choose Options > Refresh.
 

Note: In previous releases, you needed to unassign drive letters. You no longer need to unassign drive letters. This release includes the utility, Oracle Object Link Manager, which automatically unassigns link names.

The hard disks that access the shared area may be different from node to node. The logical partitions, however, that reside on the hard disks must be identical on all nodes.

For example, Node 1 may look like:

Node 2 may look like:

On Node 1, the logical partition E is defined as \Device\Harddisk1\Partition1. On Node 2, it is defined as \Device\Harddisk2\Partition1. Even though these map to different disks, they map to the same space on the shared disk.
 

Note: Oracle Database Configuration Assistant requires at least 10 logical partitions.

Step 4: Assign Symbolic Link Names

The Oracle8i Enterprise Edition CD-ROM contains ASCII files (in the \OPS_PREINSTALL directory), with symbolic link names already associated with raw partitions for a two-node cluster, supporting a database type created with the Oracle Database Configuration Assistant.

When the Oracle Database Configuration Assistant creates the database, it verifies that the symbolic link names to the extended partitions have been created and stores the files in the raw devices. The names of the partitions use the following format:

\\. \SYMBOLIC_LINK_NAME

The symbolic name uses the database name and the file type.

For example, you can create a symbolic link called OP_REDO1_1 to the second logical partition on the second physical disk:

OP_REDO1_1 \DEVICE\HARDDISK2\PARTITION2

where OP is the database name and REDO1_1 is the REDO log file.

This release includes a new utility, the Oracle Object Link Manager. Oracle Object Link Manager (GUIORACLEOBJMANAGER.EXE) is a GUI utility that enables you to assign the logical partitions symbolic link names. When you install Object Link Manager, a service named ORACLEOBJSERVICE is installed on each node. This service monitors symbolic link changes and updates all nodes when changes occur on one node.

To assign symbolic link names, perform the following tasks:

1. Refer to the Oracle8i Parallel Server Setup and Configuration Guide, Chapter 2, "Pre-Installation", for the symbolic link names required for Oracle Database Configuration Assistant files.




In addition, add additional entries for log files if your cluster contains more than two nodes or your node numbers are not 0 and 1.

2. Make sure the ORACLEOBJSERVICE is running on all nodes:
1. Double-click the Services icon in the Control Panel window. The Services dialog box appears.
2. Select ORACLEOBJSERVICE.
3. Click Start.
4. Click Close to dismiss Services dialog box.

 

 

3. To run the Object Link Manager, use the following command on one node in the cluster:

C:> GUIORACLEOBJMANAGER.EXE

The Object Link Manager appears.

4. To add a mapping:
1. Select the row containing the partition that you want to assign a link name.
2. Click on the highlighted row to invoke the Edit window.
3. Enter the new link name required for the Oracle Database Configuration Assistant file in the New Link Name column. For example, if the database name is OP, add OP_SYSTEM1 for the name of the SYSTEM tablespace data file.
4. Press Enter.




Repeat steps a to d for any additional edits.

5. Choose Options > Commit to save all changes to disk.
6. Verify all mappings are correct using Object Link Manager.

 

 

5. On all nodes in the cluster, use the Object Link Manager to verify that symbolic links are correct. If you make any changes, choose the Commit menu item.




The logical partitions and their symbolic links appear on the node from which the Oracle Object Manager application is run. Link names may appear in upper case; however, the names are case insensitive.


To force all active nodes to re-synchronize the links, choose Options > Sync Nodes. Run the Object Link Manager on all nodes to refresh the links.

 

Note: If you create or remove a partition, you need to reassign links by rerunning the Oracle Object Link Manager on the node you made the disk configuration.

You do not need to reboot after making changes. However, if a node is down, it is automatically updated when you reboot. Rebooting also generates a log file, OOBJSERVICE.LOG in the directory where you installed the Oracle Object Service.

Creating Raw Devices for Manual Database Creation

 

Use this method to create raw devices for manual database creation on a machine that does not contain a previous installation of Oracle Parallel Server on raw devices.

Step 1: Install Oracle Parallel Server Raw Devices Management Utilities

 

To install the raw devices management utilities, perform the following tasks on one node of the cluster:

1. Create a temporary directory.
2. Insert the Oracle8i Enterprise Edition CD-ROM.
3. Copy the contents of the \OPS_PREINSTALL directory to the temporary directory you created.
4. Install ORACLEOBJSERVICE by entering the following command from the temporary directory you created:

C:\> ORACLEOBJSERVICE /INSTALL

This installs the ORACLEOBJSERVICE as an automatic startup type whenever you reboot. This service monitors symbolic link changes and updates all nodes when changes occur on one node.


To remove ORACLEOBJSERVICE, use the following command:

C:\> ORACLEOBJSERVICE /REMOVE

For more information about the install and remove options, use the following command:

C:\> ORACLEOBJSERVICE /HELP

 

Note: Do not run ORACLEOBJSERVICE before using the EXPORTSYMLINKS utility described in Step 3.

Step 2: Create an Extended Partition

Extended partitions point to raw space on disk drives. Multiple logical partitions are created in these extended partitions.

Only one extended partition can be created per disk. You can use the free space in the extended partition to create multiple logical partitions or use all or part of it when creating volume sets or other kinds of volumes for fault-tolerance purposes.

You will need to create a logical partition for each log file, control file, and data file associated with the database. The number of raw devices created depends on the number of the data files, redo log files and control files you plan to create. Oracle Corporation recommends a logical partition of 100 MB.

To create an extended partition, perform the following tasks:

1. Shut down all nodes except one of the nodes.
2. On the node that is up, choose Start > Programs > Administrative Tools > Disk Administrator.




The Disk Administrator window appears:


Note the lines display diagonally from top right to the bottom left, indicating unpartitioned devices.

3. Select an area of free space in an extended partition on a disk that is on the shared disk subsystem by clicking the mouse.




Oracle Corporation recommends you use the entire disk.

4. Choose Partition > Create Extended...




The Disk Administrator displays the minimum and maximum sizes for the extended partition:


5. Use the default maximum size, then click OK.


 

Note: Changes you have made are not saved until you choose Commit Changes Now from the Partition menu or quit the Disk Administrator.

The extended partition is created.


Note the lines now display diagonally from top left to bottom right, indicating the partition is an extended partition.

Step 3: Create Logical Partitions

Logical partitions are created on one node of the cluster. To create logical partitions in an extended partition:
 

Note: Oracle Corporation recommends you do not create more than 120 logical partitions in an extended partition.

1. On one of the nodes, select an area of free space in an extended partition by clicking the mouse on it.
2. Choose Partition > Create.




The Disk Administrator window displays the minimum and maximum sizes for the logical partition.

3. Enter the size of the logical partition, then click OK.

 

 

 

Note: You can modify file sizes later, but not the raw devices. File sizes cannot expand the size of the raw device.

4. Repeat Steps 1-3 until you have the required number of logical partitions.
5. Choose Partition > Commit Changes Now.




A confirmation dialog appears, informing you changes have been made to the disk.

6. Click Yes to acknowledge the message.




A dialog box appears, informing you the disks have been updated successfully.

7. Click OK.
8. Choose Partition > Close.

 

 

To make the changes visible, on all nodes of the cluster, choose Options > Refresh.
 

Note: In previous releases, you needed to unassign drive letters. You no longer need to unassign drive letters. This release includes the utility Oracle Object Link Manager, which automatically unassigns link names.

The hard disks that access the shared area may be different from node to node. The logical partitions, however, that reside on the hard disks must be identical on all nodes.

For example, Node 1 may look like:

Node 2 may look like:

On Node 1, the logical partition E is defined as \Device\Harddisk1\Partition1. On Node 2, it is defined as \Device\Harddisk2\Partition1. Even though these map to different disks, they map to the same space on the shared disk.

Step 4: Assign Symbolic Link Names

This release includes a new utility, the Oracle Object Link Manager. Oracle Object Link Manager (GUIORACLEOBJMANAGER.EXE) is a GUI utility that enables you to assign the logical partitions symbolic link names. When you install Object Link Manager, a service named ORACLEOBJSERVICE is installed on each node. This service monitors symbolic link changes and updates all nodes when changes occur on one node.

To assign symbolic link names, you create a .TBL file and import it into the Oracle Object Link Manager. Before you proceed, make sure you know the partition sizes and the symbolic link names you want to assign to them.

To assign symbolic links:

Use the EXPORTSYMLINKS utility to generate a list of device names and create a file named SYMMAP.TBL.

1. Use the following command line syntax:




/f:filename

If this parameter is not used, the EXPORTSYMLINKS utility exports the symbolic link mappings to the SYMMAP.TBL file in the current directory. Otherwise, the utility exports the symbolic link mappings to the file named filename.

For example:

EXPORTSYMLINKS /f:MYLINKS.TBL

The following table shows a sample disk layout.

Symbolic Name	Raw Device	Size (MB)
system1	\Device\Harddisk2\Partition1	11.98
users1	\Device\Harddisk2\Partition1	11.98
temp1	\Device\Harddisk2\Partition1	11.98
rbs1	\Device\Harddisk2\Partition1	11.98
indx1	\Device\Harddisk2\Partition2	11.98
tools1	\Device\Harddisk2\Partition2	11.98
drsys1	\Device\Harddisk2\Partition2	11.98
control1	\Device\Harddisk2\Partition3	11.98
control2	\Device\Harddisk2\Partition3	11.98
redo1_1	\Device\Harddisk2\Partition3	11.98
redo1_2	\Device\Harddisk2\Partition3	11.98

2. Modify the SYMMAP.TBL file by adding your own symbolic link names to their logical partition assignments.

 

 

 

Note: If you add or delete partitions, you must use EXPORTSYMLINKS to export the SYMMAP.TBL file again on the node you configured the disk. The .TBL file will not be valid.

3. Import the SYMMAP.TBL file into Oracle Object Link Manager with the IMPORTSYMLINKS.EXE utility.




The IMPORTSYMLINKS utility reads a .TBL file and marks the hard disk partitions with the symbolic link names. Use the following command line parameters:


/f:filename	If this parameter is not used, the IMPORTSYMLINKS utility uses the symbolic link mappings in the SYMMAP.TBL file. Otherwise, the utility uses the symbolic link mappings in the file named filename.
/8i	Use this parameter to update all active nodes.

For example:

IMPORTSYMLINKS /f:C:\TEMP\MYLINKS.TBL

 

Note: IMPORTSYMLINKS detects duplicate names and does not import mappings if duplicates are present.

4. Use the Object Link Manager to select and update the symbolic mappings.
1. Start the ORACLEOBJSERVICE by entering the following command on all nodes in the cluster:

C:\> NET START ORACLEOBJSERVICE

2. To run the Object Link Manager, use the following command on one node in the cluster:

C:> GUIORACLEOBJMANAGER.EXE

The Object Link Manager appears.




5. To add or rename a mapping:
1. Select the row containing the partition that you want to assign a link name.
2. Click on the highlighted row to invoke the Edit window.
3. Enter the new link name in the New Link Name column. For example, if the database name is OP, add OP_SYSTEM1 for the name of the SYSTEM tablespace data file.
4. Press Enter.




Repeat steps a to d for any additional edits.

5. Choose Options > Commit to save all changes to disk.
6. Verify all mappings are correct using Object Link Manager.

 

 

6. On all nodes in the cluster, start the ORACLEOBJSERVICE
1. Double-click the Services icon in the Control Panel window.




The Services dialog box appears.

2. Select ORACLEOBJSERVICE.
3. Click Start.
4. Click Close to dismiss Services dialog box.

 

 

7. On all nodes in the cluster, use the Object Link Manager to verify that symbolic links are correct.




The logical partitions and their symbolic links appear on the node from which the Oracle Object Manager application is run. Link names may appear in upper case; however, the names are case insensitive.


To force all active nodes to re-synchronize the links, choose Options > Sync Nodes. Run the Object Link Manager on all nodes to refresh the links.

 

Note: If you create or remove a partition, you need to reassign links by rerunning the Oracle Object Link Manager on the node you made the disk configuration.

You do not need to reboot after making changes. However, if a node is down, it is automatically updated when you reboot. Rebooting also generates a log file, OOBJSERVICE.LOG in the directory where you installed the Oracle Object Service.

Creating Raw Devices for Manual Database Creation with a Current Configuration

 

Use the method described in this section to create raw devices for manual database creation if you have a current configuration.

 

To create the raw devices, perform the following steps:

• Backup Raw Partitions
• Step 1: Install Oracle Parallel Server Raw Devices Management Utilities
• Step 2: Create an Extended Partition
• Step 3: Create Logical Partitions
• Step 4: Assign Symbolic Link Names

 

 

Backup Raw Partitions

 

To back up the raw partitions, perform the following tasks:

1. Start the OSD layer, as described in your vendor documentation. Perform diagnostics on the clusterware as described in your vendor documentation.
2. Backup raw partitions using OCOPY. Enter the following syntax:

C:\> OCOPY \\.\PHYSICALDRIVEN NEW_FILE

where:

• PHYSICALDRIVE is the physical drive that holds a single raw database file
• N is the number(s) representing each of the physical drives in the system
• NEW_FILE is the name and location of the backup copy

 

 

For example, to backup the logical partition for a system tablespace to a file, enter:

C:\> OCOPY \\.\OPS_SYSTEM1 OPS_SYSTEM1

Use your existing partitions and symbolic link names. Oracle Corporation recommends you backup logical partitions to files with the same name. For example, backup \\.\OPS_SYSTEM1 to a file named OPS_SYSTEM1. 

See: Oracle8i Administrator's Guide for Windows NT, Chapter 11, Backing Up and Recovering Database Files, on using OCOPY.

Step 1: Install Oracle Parallel Server Raw Devices Management Utilities

 

To install the raw devices management utilities, perform the following tasks on one node of the cluster:

1. Create a temporary directory.
2. Insert the Oracle8i Enterprise Edition CD-ROM.
3. Copy the contents of the \OPS_PREINSTALL directory to the temporary directory you created.
4. Install ORACLEOBJSERVICE by entering the following command from the temporary directory you created:

C:\> ORACLEOBJSERVICE /INSTALL

This installs the ORACLEOBJSERVICE as an automatic startup type whenever you reboot. This service monitors symbolic link changes and updates all nodes when changes occur on one node.


To remove ORACLEOBJSERVICE, use the following command:

C:\> ORACLEOBJSERVICE /REMOVE

For more information about the install and remove options, use the following command:

C:\> ORACLEOBJSERVICE /HELP

 

Note: Do not run ORACLEOBJSERVICE before using the EXPORTSYMLINKS utility described in Step 3.

Step 2: Create an Extended Partition

 

Follow the steps in the previous section, if you need to create an extended partition for additional logical partitions.

Step 3: Create Logical Partitions

 

Follow the steps in the previous section, to create additional logical partitions in the extended partition.

Step 4: Assign Symbolic Link Names

 

This release includes a new utility, the Oracle Object Link Manager. Oracle Object Link Manager (GUIORACLEOBJMANAGER.EXE) is a GUI utility that enables you to assign the logical partitions symbolic link names. When you install Object Link Manager, a service named ORACLEOBJSERVICE is installed on each node. This service monitors symbolic link changes and updates all nodes when changes occur on one node.

To verify and assign symbolic link names, use the EXPORTSYMLINKS utility to generate a list of device names and create a file named SYMMAP.TBL. If valid symbolic mappings exist in a .TBL file, you can also import that file.

To use the EXPORTSYMLINKS utility:

1. Use the following command line syntax:




/f:filename

If this parameter is not used, the EXPORTSYMLINKS utility exports the symbolic link mappings to the SYMMAP.TBL file in the current directory. Otherwise, the utility exports the symbolic link mappings to the file named filename.

For example:

EXPORTSYMLINKS /f:MYLINKS.TBL

The following table shows a sample disk layout.


Symbolic Name	Raw Device	Size (MB)
system1	\Device\Harddisk2\Partition1	11.98
users1	\Device\Harddisk2\Partition1	11.98
temp1	\Device\Harddisk2\Partition1	11.98
rbs1	\Device\Harddisk2\Partition1	11.98
indx1	\Device\Harddisk2\Partition2	11.98
tools1	\Device\Harddisk2\Partition2	11.98
drsys1	\Device\Harddisk2\Partition2	11.98
control1	\Device\Harddisk2\Partition3	11.98
control2	\Device\Harddisk2\Partition3	11.98
redo1_1	\Device\Harddisk2\Partition3	11.98
redo1_2	\Device\Harddisk2\Partition3	11.98

2. Only links mapped to a valid shared disk and partition are exported. Duplicate symbolic links are indented. Check the SYMMAP.TBL file carefully for the following:
• Duplicate symbolic link names
• Symbolic link names point to partitions which are not logical partitions
• Symbolic link names point to logical partitions which are not part of a valid file system
• Symbolic link names are missing

 

 

If any of these issues exist, see the Troubleshooting section in Chapter 4, "Managing Raw Devices" before proceeding.

3. Modify the SYMMAP.TBL file as needed.

 

 

 

Note: If you add or delete partitions, you must use EXPORTSYMLINKS to export the SYMMAP.TBL file again on the node you reconfigured the disk. The .TBL file will not be valid.

4. Import the SYMMAP.TBL file into Oracle Object Link Manager with the IMPORTSYMLINKS.EXE utility.




The IMPORTSYMLINKS utility reads a .TBL file and marks the hard disk partitions with the symbolic link names. Use the following command line parameters:


/f:filename	If this parameter is not used, the IMPORTSYMLINKS utility uses the symbolic link mappings in the SYMMAP.TBL file. Otherwise, the utility uses the symbolic link mappings in the file named filename.
/8i	Use this parameter to update all active nodes.

For example:

IMPORTSYMLINKS /f:C:\TEMP\MYLINKS.TBL

 

Note: IMPORTSYMLINKS detects duplicate names and does not import mappings if duplicates are present.

5. Use the Object Link Manager to select and update the symbolic mappings.
1. Start the ORACLEOBJSERVICE by entering the following command on all nodes in the cluster:

C:\> NET START ORACLEOBJSERVICE

2. To run the Object Link Manager, use the following command on one node in the cluster:

C:> GUIORACLEOBJMANAGER.EXE

The Object Link Manager appears.




6. To add or rename a mapping:
1. Select the row containing the partition that you want to assign a link name.
2. Click on the highlighted row to invoke the Edit window.
3. Enter the new link name in the New Link Name column. For example, if the database name is OP, add OP_SYSTEM1 for the name of the SYSTEM tablespace data file.
4. Press Enter.




Repeat steps a to d for any additional edits.

5. Choose Options from the menu and then choose the Commit menu item to save all changes to disk.
6. Verify all mappings are correct using Object Link Manager.

 

 

7. On all nodes in the cluster, start the ORACLEOBJSERVICE
1. Double-click the Services icon in the Control Panel window. The Services dialog box appears.
2. Select ORACLEOBJSERVICE.
3. Click Start.
4. Click Close to dismiss Services dialog box.

 

 

8. On all nodes in the cluster, use the Object Link Manager to verify that symbolic links are correct.




The logical partitions and their symbolic links appear on the node from which the Oracle Object Manager application is run. Link names may appear in upper case; however, the names are case insensitive.


To force all active nodes to re-synchronize the links, choose Options > Sync Nodes menu item. Run the Object Link Manager on all nodes to refresh the links.

 

Note: If you create or remove a partition, you need to reassign links by rerunning the Oracle Object Link Manager on the node you made the disk configuration.

You do not need to reboot after making changes. However, if a node is down, it is automatically updated when you reboot. Rebooting also generates a log file, OOBJSERVICE.LOG in the directory where you installed the Oracle Object Service.