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Backing up your files protects against loss or corruption of your data. Use the Tivoli Storage Manager backup-archive client to back up your files regularly, regardless of whether they are resident, migrated, or premigrated. Back up and restore your migrated and premigrated files in the same manner as you back up and restore files that reside on your local file systems.
See IBM Tivoli Storage Manager for UNIX: Backup-Archive Clients Installation and User's Guide for information about backing up and restoring files.
You can back up and migrate your files to the same Tivoli Storage Manager server or to different Tivoli Storage Manager servers. If you back up and migrate files to the same server, the HSM client can verify that current backup versions of your files exist before you migrate them.
To restore stub files rather than backup versions of your files, use the restoremigstate option with the Tivoli Storage Manager backup-archive client restore command. This is useful if one or more of your local file systems is damaged or lost. Your migrated and premigrated files remain intact, and you need only restore your stub files. To recreate stub files for any migrated or premigrated files that are not backed up, use the dsmmigundelete command.
If you back up files to one server and migrate them to a different server, the HSM client cannot verify that current backup versions of your files exist before you migrate them. Use the backup-archive client to restore the actual backup versions only. You cannot use the backup-archive client to restore stub files for your migrated files. Use the dsmmigundelete command to recreate stub files for any migrated or premigrated files that are lost.
If you back up and migrate files to the same server, you can assign a management class to files specifying that current backup versions of your files must exist on the migration server before the files migrate. The default management class includes this requirement. The HSM client checks for backup versions of files only on the server to which it migrates your files. If a current backup version of a file does not exist on that server, the file is not migrated.
If you back up files to one server and migrate them to a different server, the HSM client cannot verify that current backup versions of your files exist before it migrates them. Any management class that you assign to files must specify that current backup versions are not required prior to migration. Otherwise, you cannot migrate your files.
To back up your files after you migrate them, assign a management class to your files that does not include the requirement for an existing backup version.
If you back up files to the same server to which you migrate them, files are copied from the migration destination to the backup destination. Files are not recalled to your local file system.
Valid for AIX JFS file systems only:
A backup of a migrated file signals a recall if it has been touched within the last two minutes. The file is premigrated.
If you back up files to a different server after you migrate them, the backup-archive client accesses the files using:
For more information about recall modes, see "Migrating Your Files".
You can back up a premigrated file in the same manner that you back up a resident file. Whether you back up a file to the same server to which it was premigrated or to a different server, a copy of the file is sent from your local file system to storage. The HSM client does not copy the file from the migration destination to the backup destination.
If you back up and migrate files to the same server, you can:
If you back up and migrate files to a different server, you can:
For more information about restoring backup versions and stub files for migrated or premigrated files, see IBM Tivoli Storage Manager for UNIX: Backup-Archive Clients Installation and User's Guide.
If you back up files after they are migrated to the same server, you can restore migrated files using one of the following methods:
Set the restoremigstate option to no in your dsm.opt file. The file becomes a resident file. The migrated copy of your file is removed from Tivoli Storage Manager storage when it expires. Specify the expiration with the migfileexpiration option in your dsm.sys file.
Set the restoremigstate option to yes in your dsm.opt file.
For AIX GPFS, Linux86 GPFS, Solaris VxFS, and HP-UX VxFS file systems only: Files with ACLs are restored to a resident state, even when you specify restoremigstate yes.
If a backup version of a migrated file does not exist, you cannot use the backup-archive client to restore a stub file for that file. To recreate a stub file for a migrated file, use the dsmmigundelete command.
For more information about these options, see Migfileexpiration and Restoremigstate.
If you back up files to one server and migrate them to a different server, use one of the following methods to restore your migrated files:
Use the dsmmigundelete command. If a migrated copy of your file exists in storage, the migrated copy of the file is removed from storage when it expires. The file becomes a resident file. Specify the expiration with the migfileexpiration option in your dsm.sys file.
If you back up and migrate files to the same server, and backup versions of your files exist, use the backup-archive client to restore your stub files.
If you back up and migrate files to a different server and your stub files are erased or corrupted, use the dsmmigundelete command to recreate them.
The dsmmigundelete command creates stub files for any premigrated files for which an original file does not exist on your local file system.
File | Description |
---|---|
Migrated files | Recreates a stub file for a migrated file if a corresponding stub file does not exist on your local file system, and the migrated file was not marked for expiration. |
Premigrated files | Creates a stub file for a premigrated file if a corresponding original file does not exist on your local file system, and the premigrated file was not marked for expiration. |
File | Description |
---|---|
Migrated files | Recreates a stub file for a migrated file if a corresponding stub file does not exist on your local file system, whether the migrated file was marked for expiration or not. |
Premigrated files | Creates a stub file for a premigrated file if a corresponding original file does not exist on your local file system, whether the premigrated file was marked for expiration or not. |
When you enter the dsmmigundelete command:
Attention: The dsmmigundelete command does not support hardlinked files. If you attempt to recreate a stub file for a hardlinked file, a stub file is not recreated unless all of the files that are hardlinked together are deleted from your local file system. When one file in a set of hardlinked files is migrated, all of the hardlinked files in the set become stub files. When the dsmmigundelete command recreates a stub file for a hardlinked file, the stub file has the same name as the file that was originally migrated. Stub files are not recreated for any other files that were previously in the hardlinked set of files.
For more information about using the dsmmigundelete command, see dsmmigundelete.
If you lose an entire file system and you attempt to restore backup versions of all your files, including those that are migrated and premigrated, your file system might run out of space. If your file system runs out of space during the restore process, the HSM client must begin migrating files to storage to make room for additional restored files, thereby slowing the restore process.
Rather than restoring backup versions of all your files, do one of the following:
Using one of these methods restores your file system to its state as of the last incremental backup. Premigrated files change to a migrated state.
Follow the steps below to restore your file system if you back up and migrate files to the same server and you have backup versions of your migrated and premigrated files. Enter commands to restore your file system in the exact order that is presented. Otherwise, you might not obtain the results that you want.
dsmc restore -restoremigstate=yes -sub=yes "/home/*"
Enter the dsmc restore command with the restoremigstate option set to yes. The HSM client restores backup versions of resident files and restores stub files for migrated and premigrated files.
Follow these instructions to restore your file system if you back up files to one server and migrate them to another, or if backup versions are not available for migrated and premigrated files.
dsmc restore -dirsonly -sub=yes "/home/*"
When you use the dirsonly option with the dsmc restore command, only those backed-up directories are restored for your file system. For each directory, attributes such as access permissions or, on an AIX workstation, an access control list, are restored.
When you use the dirsonly option with the dsmc restore command, only those backed up directories for the file systems that you specify are restored.
dsmmigundelete /home
For more information about the dsmmigundelete command, see dsmmigundelete.
dsmc restore -replace=no -sub=yes "/home/*"
To restore a disk in the event of disk loss, restore your:
If you can run the backup-archive client, you can recover files. If you can run the HSM client, you can recreate stub files for your migrated files and create stub files for your premigrated files. If you lose the file system that contains your Tivoli Storage Manager clients, you must reinstall the clients before you can recover your files. If you lose the file system that contains the operating system and communications software, you must recover them before you can connect to your server. To minimize the impact of such losses, create a set of installation media that will restore your system to a state that permits contact with the server. The installation media should contain:
The files that you need depend upon the communications package that you use. Consult your operating system and communications software manuals for help in setting up your installation media.
Use these instructions to restore your file systems if you back up and migrate files to the same server. Enter commands to restore your file systems in the exact order that is presented in the following steps. Otherwise, you might not obtain the results that you want.
The backup-archive client restores backup versions of resident files and stub files for migrated and premigrated files. For example, to restore the /home file system, enter:
dsmc restore -restoremigstate=yes -sub=yes "/home/*"
To restore file systems to different servers for backup and migration, follow these steps:
dsmc restore -dirsonly -sub=yes "/home/*"
When you use the dirsonly option with the dsmc restore command, only those backed up directories for the file systems that you specify are restored. For each directory, attributes such as access permissions or, on an AIX workstation, an access control list, are restored.
dsmmigundelete /home
For more information about the dsmmigundelete command, see dsmmigundelete.
dsmc restore -replace=no -sub "/home/*"