IBM Tivoli Software IBM Tivoli Software

[ | | | ]


IBM Tivoli Storage Manager for Space Management for UNIX: User's Guide


Reconciling Your File Systems

Note:
To perform tasks in this chapter, you must have root user authority.

To keep your local file systems synchronized with the Tivoli Storage Manager server that you contact for space management services, the HSM client automatically reconciles your file systems at intervals that you set. You, as root user, also can start reconciliation manually.

This chapter describes the reconciliation options that you set, the reconciliation tasks that the HSM client performs, and the manual performance of these tasks.


Starting Automatic Reconciliation

The HSM client automatically reconciles each file system for which space management is active. To specify how often reconciliation runs, modify the setting on the reconcileinterval option in your dsm.sys file. The default is every 24 hours. To specify how many file systems automatically are reconciled at one time, modify the setting on the maxreconcileproc option in your dsm.sys file. The default is three file systems.

When you modify or delete a migrated or premigrated file from your local file system, an obsolete copy of the file remains in storage. During automatic reconciliation, any obsolete copies of your migrated or premigrated files are marked for expiration. When the copies expire, they are removed from the server. To specify how many days a migrated or premigrated file remains in storage after you recall and modify or erase it from your local file system, modify the setting on the migfileexpiration option in your dsm.sys file. The default is seven days.

For more information about these options, see "Using Options".

Table 14 describes the tasks that automatic reconciliation performs on files and file systems.

Table 14. Reconciliation Tasks

Object Reconciliation Tasks
Migrated files
  • Verifies that a stub file exists on your local file system for each migrated file in storage.
  • Marks a migrated file for expiration if:
    • You deleted the stub file from your local file system
    • You recalled the file and modified it.
  • Removes a migrated file from storage if it expired.
  • Updates the status file.

Premigrated files
  • Verifies that premigrated files are still valid.
  • Marks a premigrated file for expiration if:
    • You deleted the file from your local file system
    • You accessed the file and modified it.
  • Removes a copy of a premigrated file from storage if it expired.

Stub files Records, in the orphan.stubs file, the name of any file for which a stub file exists on your local file system, but a migrated file does not exist in storage. See "Resolving Orphaned Stub Files" for more information.
Premigrated files database Valid for AIX JFS only

  • Deletes invalid entries from the premigrated files database.
  • Completes reorganization of the premigrated files database that is stored in the .SpaceMan directory if processing is interrupted.
  • Clears the database if the premigrated files database is corrupted. All previously premigrated files become resident files.
Status file Updates the following information in the status file:
  • Number of premigrated files
  • Number of premigrated blocks
  • Number of migrated files
  • Number of migrated blocks.
Note:
Migration and recall processes update status information dynamically. If any other process changes the state of a file, the status file does not reflect the change until reconciliation is run.

Reconciling Your File Systems Manually

You can perform reconciliation tasks manually for one or more file systems, or synchronize your client and server only. The sections that follow describe each task. For example, if you recall a large number of migrated files, modify them, and selectively migrate them to storage, two copies of each file reside in storage. The unmodified copy of each file now is obsolete. If you set the migfileexpiration option to zero, you can run reconciliation immediately to delete the obsolete copies from storage and create available space for your migrated files.

Perform All Reconciliation Tasks

To manually perform all reconciliation tasks for one or more file systems, follow these steps:

  1. Click Space Manager in the Hierarchical Storage Management window.
  2. Highlight the file systems that you want to reconcile.
  3. Click Selected->Reconcile (Synchronize and Build) to view the Reconcile window. Both check buttons for Synchronize Client and Server and Build a Migration Candidates List are selected.

    If you select more than one file system, a window displays for each one. Select the window that you want to view.

  4. Click Start to begin reconciling the file system. The Reconcile Status window displays.
  5. Click Stop in the Reconcile Status window to discontinue file system reconciliation.
    Note:
    The file system might not be completely synchronized, or the migration candidates list might not be completely built. If either occurs, the file system will not be reconciled until reconciliation runs again.
  6. Click Close to close the Reconcile Status window.

After you run reconciliation, check the orphan.stubs file in the .SpaceMan directory for each file system that you reconciled to determine if any orphaned stub files were located. If the orphan.stubs file lists file names, see "Resolving Orphaned Stub Files".

To view the migration candidates list for your file system, click the file system in the Space Manager window. Click Selected->Display Migration Candidates List.

Synchronize Your Client and Server

When you synchronize your file system, you update other space-management-related information. To synchronize your client and server manually, follow these steps:

  1. Click Space Manager in the Hierarchical Storage Management window.
  2. Highlight the file systems that you want to synchronize.
  3. Click Selected->Synchronize Client and Server to view the Reconcile Status window. If you select more than one file system, the HSM client displays a window for each one. Select the window that you want to view.
  4. Click Stop in the Reconcile Status window to discontinue synchronization.
    Note:
    The file system might not be completely synchronized until you run Synchronize Client and Server, run all reconciliation tasks manually, or run reconciliation automatically.
  5. Click Close to close the Reconcile Status window.

After you synchronize the client and server, check the orphan.stubs file in the .SpaceMan directory for each file system that you reconciled to determine if any orphaned stub files were located. If file names are listed in the orphan.stubs file, see Resolving Orphaned Stub Files. See Appendix B, The .SpaceMan Directory for information about the .SpaceMan directory.


Resolving Orphaned Stub Files

An orphaned stub file is a stub file for which a corresponding migrated file in storage is not located. If orphaned stub files exist in your file systems, the HSM client records information about these files in the orphan.stubs file during reconciliation. If you set the errorprog option in your dsm.sys file, a message is sent to the program that you specified with this option during automatic reconciliation.

Possible situations in which stub files might become orphaned include the following:

To check for orphaned files, specify yes on the checkfororphans option in your dsm.sys file. When orphaned files are located, their names are recorded in the .SpaceMan/orphan.stubs file. If you select yes, a full file system tree traversal is performed. In this instance, you cannot run the dsmautomig command in parallel with the dsmreconcile command.


Reconciling Your File Systems Using Commands

You can use the dsmreconcile command to perform reconcile tasks rather than using the graphical user interface. If you reconcile several file systems, increase the value on the reconcileinterval option in your dsm.sys file to reduce the impact that the dsmreconcile command might have on system performance.

Use the dsmreconcile command to perform these reconciliation tasks:

Table 15 provides several examples of reconciliation tasks that you can perform.

Table 15. Examples Using the dsmreconcile Command

To Do This Enter This
Reconcile the /home file system. dsmreconcile /home
Synchronize the /home file system. dsmreconcile -f /home

The dsmreconcile command traverses your managed file systems under the following conditions:

When you upgrade from a previous version of the HSM client, the next run of dsmreconcile on a previously managed file system forces a full tree traversal. This process occurs only once for each managed file system to update the client and server databases to the new format.

The dsmautomig command can run in parallel with dsmreconcile if it is not necessary for the dsmreconcile command to traverse your file system. The exception to this is when dsmreconcile queries the server for a list of migrated files.

For command information about dsmreconcile, see dsmreconcile. For command information about dsmautomig, see dsmautomig.


Using Space Management Daemons

The HSM client uses the space monitor daemon, the recall daemon, and the scout daemon to manage your file systems automatically. They start when you add space management to your file systems and modify your options. The sections that follow describe each space management daemon.

Start the Space Monitor Daemon

The space monitor daemon monitors space usage on all file systems to which you add space management, and it starts threshold migration whenever necessary. To check space usage more frequently or less frequently, change the value on the checkthresholds option in your dsm.sys file.

To reconcile your file systems more frequently or less frequently, change the value on the reconcileinterval option in your dsm.sys file. See "Using Options" for more information about these options.

For AIX file systems only: The space monitor daemon starts automatically when you mount your file system and add space management to it. If the space monitor daemon stops running, enter the dsmmonitord command to start it.

When you change the option values that the space monitor daemon uses, the new values are not effective until you restart your system, or you stop and restart the space monitor daemon.

Start the Recall Daemon

The recall daemon recalls migrated files from storage to your local file system. A recall daemon can recall only one file at a time; however, you can run more than one recall daemon at the same time. To set the minimum and maximum number of recall daemons that you want to run at one time, use the minrecalldaemons and maxrecalldaemons options in your dsm.sys file. The minimum number of recall daemons that you can run at the same time is one. The default is three. The maximum number of recall daemons that you can run at the same time is 99. The default is 20. See Minrecalldaemons and Maxrecalldaemons for more information about these options.

The maximum number of recalls that you can set depends on the number of concurrent recalls that normally occur on your system. If all recall daemons are busy, another file cannot be recalled until a recall daemon is available. If a frequently-used application opens several files at the same time, and that application uses all available recall daemons because all files are migrated, increase the value that you set on the maxrecalldaemons option. If a recall daemon is unable to start another process that is attempting to access a migrated file, that process cannot continue until a recall daemon is available.

The master recall daemon starts automatically when you mount your file system and add space management to it. If a recall daemon is not running, enter the dsmrecalld command to start one.

When you change the option values that the recall daemons use, the new values are not effective until you restart your system, or you stop and restart the master recall daemon.

Start the Scout Daemon

The scout daemon automatically searches for candidates on each file system for which space management is active. To specify how regularly a search for candidates will start on a file system, modify the setting on the candidatesinterval option in your dsm.sys file. If you modify the setting to the maximum value of 9999, the scout daemon does not search in regular cycles for migration candidates. It searches for migration candidates only on requests from the automigration process.

Stop the Space Management Daemons

To stop the space monitor, master recall or subordinate recall daemons, or scout daemon, follow these steps:

  1. Enter the dsmq command to obtain the recall ID and the recall daemon process ID for each recall process that is in the queue. For more information, see dsmq.
  2. Enter the dsmrm command to remove each recall process from the queue. For more information, see dsmrm.
  3. Enter ps -ef | grep dsm to verify that both the space monitor daemon and the master recall daemon are running.
  4. Enter the kill -15 command with the process identifier number to stop the daemons.
    Note:
    Stopping a master recall daemon stops all subordinate daemons.
  5. Verify that the daemons no longer are running.


[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]