User's Manual

HP StorageWorks File System Extender Software user guide 223
The backup process
The following steps describe FSE backup process in general. Except for the volume snapshot creation,
which is platform specific, the process is the same on all platforms:
1. FSE server is internally suspended. Operation of all running Partition Managers is temporarily blocked,
in order to achieve a consistent state of all File System Catalogs (FSCs) and other entities that will be
backed up.
2. Data from transaction log files of Hierarchical Storage Management Databases (HSMDBs) on the FSE
clients are committed to the main databases, and then the transaction log files are removed. This action
achieves the required consistency of HSMDBs.
3. Transaction log files of File System Catalogs (FSCs) are committed to the main databases. This action
achieves the required consistency of FSCs.
4. Snapshots of the volumes with FSE databases and system files are created.
5. FSE server is resumed. Operation of all running Partition Managers is unblocked so that Partition
Managers can process existing job requests and accept new ones.
6. Backup data is collected, archived, and compressed into a single backup image file, which is
temporarily stored in FSE disk buffer. On all supported platforms, backup image files use the
.tar.bz2 file format.
7. According to the specified backup destination, the backup image is copied to disk (local or remote disk
volume or share), tape (FSE medium in the backup FSE media pool), or both.
8. Transaction log files of File System Catalogs (FSCs), which were committed in step 3, are removed.
9. Snapshots of disk volumes are removed.
NOTE: While other steps of the backup process typically only take a few minutes, the step 6 is usually
long lasting and may take considerable amount of time. The main reason is data compression.
In the FSE implementation, only one backup process can be running at the same time. Starting an
additional backup process is prevented.
The backup progress is recorded in the backup.log file. Once backup is finished, it reports barcodes of
the backup FSE media where backed up data is stored. Backup start and stop times are written to the
fse.log file and can help estimate the time needed for backup.
Backup media management
If tape backup will be used as a backup destination, you have to configure a single backup FSE media
pool and prepare backup FSE media. In order to ensure safety of backup data and prevent data loss,
special attention is required with management of backup FSE media.
NOTE: As an FSE administrator, you are responsible for preparation, allocation, and correct usage of
backup FSE media as well as for keeping track of already used backup media and their contents. Backup
media management tasks are crucial for successful implementation of your FSE backup policy.
In case the FSE backup policy includes scheduled backups, the options --medium and --init of the
fsebackup command help organizing and reusing backup FSE media.
CAUTION: If old media will be reused for FSE backup storage, you must ensure that they are not
damaged or too worn out. Failing to do so may result in the unusable FSE backup image and -
consequently - permanent data loss on the FSE server.
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MODULES_LOADED_ON_BOOT="dm-snapshot"