Managing Storage Checkpoints

A Storage Checkpoint is like an online backup of a database that contains a point-in-time database image. Storage Checkpoints can later be used to restore the image of a datafile, a tablespace, or the entire database to any earlier state recorded by the Storage Checkpoints.

VERITAS Storage Foundation for Oracle uses the VxDBA repository to determine the list of tablespaces, datafiles, and file systems for Storage Checkpoint creation and removal.

For more information about Storage Checkpoints, see Understanding Storage Checkpoints and Storage Rollback and Using Storage Checkpoints and Storage Rollback for Backup and Restore.

Creating a Storage Checkpoint

You have the option to create an offline, online, or instant Storage Checkpoint. If the database is online when the Storage Checkpoint is created, VERITAS Storage Foundation for Oracle switches the database to online backup mode before creating the Storage Checkpoint. Once the Storage Checkpoint is created, VERITAS Storage Foundation for Oracle switches the database back to its normal operation mode.

For the instant option, the database should be online and it can be running in either ARCHIVELOG or NOARCHIVELOG mode. You can only roll back the entire database to an instant Storage Checkpoint. After the rollback is complete, you need to perform Oracle database instance recovery. Rolling the database forward is not supported; that is, you cannot apply archived redo logs.

In addition to creating a Storage Checkpoint, the GUI automatically backs up the associated control files, initialization file, and log information. Suppose that you made a structural change to your database, and then needed to roll back the database to a Storage Checkpoint that was created before the structural change. The Storage Rollback would only be successful if you could also reconstruct the database to the same structure that it was when the Storage Checkpoint was created. You can recreate the previous database structure using the control files, initialization file, and log information that were backed up when the Storage Checkpoint was created.

Prerequisites

• Enable ARCHIVELOG mode before taking online Storage Checkpoints. See Backing Up and Recovering the Database Using Storage Checkpoints and Using Storage Checkpoints and Storage Rollback for Backup and Restore.

  To create a Storage Checkpoint

1. Click the Storage Checkpoints icon in the object tree. (You may need to expand the tree view to find the icon.)
2. Select one of the following methods to create a Storage Checkpoint.
   • From the menu bar, select Storage Checkpoints > Create Storage Checkpoint.

   or

   • Right click the Storage Checkpoints icon to bring up a pop-up menu. Then, click Create Storage Checkpoint.

   The Create a Storage Checkpoint wizard is displayed.

3. Verify the Oracle SID, which is the Oracle System Identifier, for which you are creating the Storage Checkpoint. This is a read-only field.
4. Select one of the following options:
   • To create an online Storage Checkpoint, click the Online button.
   • To create an offline Storage Checkpoint, click the Offline button.
   • To create an instant Storage Checkpoint, click the Instant button.

5. If you want to remove the Storage Checkpoint when the file system becomes full, click the Remove This Storage Checkpoint button.

   or

   If you want to retain the Storage Checkpoint when the file system becomes full, click the Retain This Storage Checkpoint button.

6. Click Create to continue.
7. At the prompt, click Yes to proceed with creating the Storage Checkpoint.

   If the Storage Checkpoint was successfully created, you will receive a confirmation message. To see details, click the Show Details checkbox. The details are displayed in a pop-up window.

   Click OK to continue.

Viewing Storage Checkpoint Details

  To view the details of a Storage Checkpoint

1. Click a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)

   The Storage Checkpoint information is displayed on the right side of the window.

2. To view file system quota information for the Storage Checkpoint, click the File System Quota tab at the top of the window, just above the Storage Checkpoint details.

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     Note    The file system quota information is only available for disk layout version 6.

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Mounting a Storage Checkpoint

You can mount and write to Storage Checkpoints just as you can do with any file system. See Using Storage Checkpoints and Storage Rollback for Backup and Restore for more information.

  To mount a Storage Checkpoint

1. Click a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)
2. Select one of the following methods to mount the Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Mount Storage Checkpoint.

   or

   • Right click the Storage Checkpoint you want to mount to bring up a pop-up menu. Then click Mount Storage Checkpoint.

   The Mount a Storage Checkpoint wizard then displays.

3. Verify that you are mounting the correct Storage Checkpoint and click Next to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.
4. On the second screen, enter the mount point (absolute path) where the Storage Checkpoint should be mounted.

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     Note    The directory containing the mount point must be writable by the database administrator group. You should have created this group during installation. If not, create the group before mounting the Storage Checkpoint.

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5. To mount the Storage Checkpoint as read-only, click Read Only.

   or

   To mount the Storage Checkpoint as read-write, click Read/Write. This will allow you to make changes to the Storage Checkpoint.

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     Note    When you select the Read/Write option, the GUI creates an identical Storage Checkpoint with the same name plus a wr001 suffix, where 001 is a sequential number. The GUI mounts the new Storage Checkpoint and leaves the original Storage Checkpoint unmounted. This allows you to roll back to the original Storage Checkpoint.

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6. Click Mount to mount the Storage Checkpoint.
7. At the prompt, click Yes to proceed with mounting the Storage Checkpoint.

   When you have finished viewing the details in the Confirmation dialog, click OK to continue.

Unmounting a Storage Checkpoint

  To unmount a Storage Checkpoint

1. Click a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)

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     Note    If you want to unmount a Storage Checkpoint that was originally mounted with the Read/Write option, you should unmount the new Storage Checkpoint that was automatically created by the GUI, which is the Storage Checkpoint that contains the wr001 suffix, where 001 is a sequential number, at the end of the name.

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2. Select one of the following methods to unmount the Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Unmount a Storage Checkpoint.

   or

   • Right click the Storage Checkpoint you want to unmount to bring up a pop-up menu. Then click Unmount Storage Checkpoint.

3. Verify that you are unmounting the correct Storage Checkpoint and click Unmount to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.
4. At the prompt, click Yes to proceed with unmounting the Storage Checkpoint.
5. A confirmation dialog is displayed. Click OK to continue.

Removing a Storage Checkpoint

Occasionally, you may need to manually remove Storage Checkpoints that are no longer needed. For example, you can remove a Storage Checkpoint on a file system to free up needed space.

Prerequisites

• Before you can remove a mounted Storage Checkpoint, you must first unmount it.

  To remove a Storage Checkpoint

1. Click a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)
2. Select one of the following methods to remove the Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Remove Storage Checkpoint.

   or

   • Right click the Storage Checkpoint you want to remove to bring up a pop-up menu. Then click Remove Storage Checkpoint.

3. At the prompt, click Yes to remove the Storage Checkpoint.

   If the Storage Checkpoint was successfully removed, you will receive a confirmation message. Click OK to continue.

Rolling Back to a Storage Checkpoint

You can roll back a database file, a list of database files, a single tablespace, or the entire database to a Storage Checkpoint. To perform a Storage Rollback, you must have a valid Storage Checkpoint. This option is not available with an instant Storage Checkpoint.

Storage Checkpoints can only be used to roll back files that are damaged due to a software error or a human error (for example, accidental deletion of a table). Because Storage Checkpoints reside on the same physical disks as the primary file system, when a file is corrupted due to a media failure, the file on the Storage Checkpoints will not be available either. In this case, you need to restore files from a tape backup.

After the files are rolled back, you may need to follow the recovery procedure described in your Oracle manuals to recover the database before the database can be used.

Rolling Back the Database to a Storage Checkpoint

Rolling back the entire database rolls back all the datafiles used by the database, except the redo logs and control files, to a Storage Checkpoint.

  To rollback the database to a Storage Checkpoint

1. Shut down the Oracle database from the GUI.
2. Click the a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)
3. Select one of the following methods to rollback to the selected Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Roll Back Storage Checkpoint.

   or

   • Right click the Storage Checkpoint to which you want to rollback to bring up a pop-up menu. Then, click Roll Back Storage Checkpoint.

   The Rollback a Storage Checkpoint wizard is displayed.

4. Verify that you are rolling back to the correct Storage Checkpoint and click Next to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.
5. On the second screen, use the drop-down menu to select the appropriate buffer size in the Rollback Buffer Size field. The default buffer size is 128K.

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     Note    The buffer size configured for reads and writes when performing a Storage Rollback can affect performance. Vary the size to determine the optimal setting for your system.

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6. Use the drop-down menu to select the appropriate number of threads in the Number of Threads field. The default number of threads is four.

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     Note    Depending on the number of CPUs available on your system and the type of volume on which the file system is located, this default setting may specify too few or too many threads.

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7. Click the Roll back a database button to indicate that you are rolling back the entire database to the Storage Checkpoint.
8. Click Next to continue. Click Roll Back to continue.

   If the Storage Rollback was successful, a confirmation message is displayed.

9. To see the Storage Rollback details, click the Show details checkbox. The details are displayed in the pop-up window.

   When you have finished viewing the details, click OK.

10. Click Yes to roll back the tablespace or tablespaces. Perform any necessary Oracle recovery. See Guidelines for Oracle Recovery for more information. (You cannot recover your database through the GUI.)
11. Restart the database from the GUI.

Rolling Back a Tablespace to a Storage Checkpoint

If a tablespace is corrupted or removed due to a software error or a human mistake, this operation rolls back all of the files of the corrupted or removed tablespace to a Storage Checkpoint.

This option is only available for offline and online Storage Checkpoints. You cannot roll back a tablespace to an instant Storage Checkpoint.

Rolling back a tablespace is used for complete recovery of the tablespace. It is not designed for point-in-time (incomplete) tablespace recovery, which is more complicated and requires interaction with Oracle Customer Support. The tablespace point-in-time recovery requires using a clone database. See Creating Clone Database for more information.

  To roll back a tablespace to a Storage Checkpoint

1. Verify that the tablespace to which you want to roll back is offline.
2. Click the a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)
3. Select one of the following methods to rollback to the selected Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Rollback a Storage Checkpoint.

   or

   • Right click the Storage Checkpoint to which you want to rollback to bring up a pop-up menu. Then, click Rollback a Storage Checkpoint.

   If the database is online, you will receive a prompt asking you if you want to continue. Click Yes to continue the Storage Rollback.

   The Rollback a Storage Checkpoint wizard is displayed.

4. Verify that you are rolling back to the correct Storage Checkpoint and click Next to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.
5. On the second screen, use the drop-down menu to select the appropriate buffer size in the Rollback Buffer Size field. The default buffer size is 128K.

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     Note    The buffer size configured for reads and writes when performing a Storage Rollback can affect performance. Vary the size to determine the optimal setting for your system.

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6. Use the drop-down menu to select the appropriate number of threads in the Number of Threads field. The default number of threads is four.

   ---

     Note    Depending on the number of CPUs available on your system and the type of volume on which the file system is located, this default setting may specify too few or too many threads.

   ---

7. Click the Rollback a Tablespace button to indicate that you are rolling back the tablespace to the Storage Checkpoint.
8. Click Next to continue. Select the tablespace, or tablespaces, you would like to roll back by clicking the appropriate checkbox in the Tablespace list.
9. Click Roll Back to continue.
10. If the Storage Rollback was successful, you will receive a confirmation message. Click OK to continue.
11. Click Yes to rollback the datafile or datafiles. Perform any necessary Oracle media recovery. See Guidelines for Oracle Recovery for more information. (You cannot recover database information through the GUI.)
12. Put the recovered tablespace back online.

Rolling Back Datafiles to a Storage Checkpoint

Rolling back datafiles rolls back database files to a Storage Checkpoint. You can also use this operation to roll back more than one datafile.

This option is only available for offline and online Storage Checkpoints. You cannot roll back a datafile to an instant Storage Checkpoint.

  To roll back datafiles to a Storage Checkpoint

1. Verify that the datafile to which you want to roll back is offline.
2. Click the a specific Storage Checkpoint in the object tree. (You may need to expand the tree view to find the Storage Checkpoint.)
3. Select one of the following methods to rollback to the selected Storage Checkpoint.
   • From the menu bar, select Storage Checkpoint > Rollback a Storage Checkpoint.

   or

   • Right click the Storage Checkpoint to which you want to rollback to bring up a pop-up menu. Then click Rollback a Storage Checkpoint.

   If the database is online, you will receive a prompt asking you if you want to continue. Click Yes to continue the Storage Rollback.

   The Rollback a Storage Checkpoint wizard is displayed.

4. Verify that you are rolling back to the correct Storage Checkpoint and click Next to continue. If you selected the wrong Storage Checkpoint, click Cancel. The information on this screen is read-only.
5. On the second screen, use the drop-down menu to select the appropriate buffer size in the Rollback Buffer Size field. The default buffer size is 128K.

   ---

     Note    The buffer size configured for reads and writes when performing a Storage Rollback can affect performance. Vary the size to determine the optimal setting for your system.

   ---

6. Use the drop-down menu to select the appropriate number of threads in the Number of Threads field. The default number of threads is four.

   ---

     Note    Depending on the number of CPUs available on your system and the type of volume on which the file system is located, this default setting may specify too few or too many threads.

   ---

7. Click the Roll back a Datafile button to indicate that you are rolling back the datafile to the Storage Checkpoint.
8. Click Next to continue.
9. Select the datafile, or datafiles, you would like to roll back by clicking on the appropriate checkbox in the Datafile list.
10. Click Roll Back to continue.
11. If the Storage Rollback was successful, you will receive a confirmation message. Click OK to continue. You are then returned to the rollback window.
12. Perform any necessary Oracle media recovery. See Guidelines for Oracle Recovery for more information.
13. Put the recovered datafile back online.

Using a Storage Checkpoint Policy for Space Management

A Storage Checkpoint policy establishes how many Storage Checkpoints you would like to keep in the event your file system becomes full. You can also determine what to do with old Storage Checkpoints when you run out of space. You should set up a Storage Checkpoint policy before creating any Storage Checkpoint schedules.

Prerequisites

• You must enable the Monitoring Agent to use the Storage Checkpoint policy.

Creating a Storage Checkpoint Policy

  To create a Storage Checkpoint policy

1. Click the Storage Checkpoints icon in the object tree. (You may need to expand the tree view to find the icon.)
2. Select one of the following methods to create a Storage Checkpoint policy.

   Right click the Storage Checkpoint icon to bring up a pop-up menu. Then, click Policy.

   The Storage Checkpoint Policy window is displayed.

3. Enter the maximum number of Storage Checkpoints to keep on the file system in the Maximum field.
4. To enable the policy, click the Enable button.
5. To remove old Storage Checkpoints if the maximum number is exceeded, click Remove Old Storage Checkpoints.

   or

   If you would like to keep old Storage Checkpoints after the maximum number is exceeded, click Retain Old Storage Checkpoints. (This option will prevent any new Storage Checkpoints from being created if the file system runs out of space.)

6. Click Policy Update to save your changes.

   If the Storage Checkpoint policy was successfully created, you will receive a confirmation message. Click OK to continue.

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     Note    If your Monitoring Agent is disabled, you will receive warning stating that you must active the Monitoring Agent in order to use the Storage Checkpoint policy.

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Disabling a Storage Checkpoint Policy

  To disable a Storage Checkpoint policy

1. Click the Storage Checkpoints icon in the object tree. (You may need to expand the tree view to find the icon.)
2. Select one of the following methods to disable a Storage Checkpoint policy.

   Right click the Storage Checkpoint icon to bring up a pop-up menu. Then, click Policy.

   The Storage Checkpoint Policy window is displayed.

3. To disable the policy, click the Disable button.
4. Click Policy Update to save your changes.

   If the Storage Checkpoint policy was successfully disabled, you will receive a confirmation message. Click OK to continue.