Blue Arc Titan SiliconServer, Руководство системного администратора

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Storage Management
220 Titan SiliconServer
When attempting to access a migrated file through a snapshot on Primary Storage, Titan will
look for the corresponding snapshot on Secondary Storage and retrieve the migrated data from
that snapshot. If the secondary file system does not contain any snapshots, then the file
contents will be retrieved from the live file system.
Virtual Volumes
If Virtual Volumes are present on Primary Storage they will be automatically created during the
first scheduled run of the Data Migration Policy.
Quota space tracking
Quotas are enforced only on the file system or Virtual Volume on which they were created. When
a file is migrated through Data Migrator, the contents are moved from one file system or Virtual
Volume to another. The result is that quotas on Primary Storage are only effective on files that
have not been migrated. To track space utilization of migrated data, quotas will need to be
manually defined on Secondary Storage. Quota restrictions on Virtual Volumes cannot be set
until after the policy has been completed.
Backup, Restore, and Replication of Migrated Files
While backing up a migrated file, NDMP will backup the entire contents of the file by retrieving it
from Secondary Storage. Additionally, the backed up file will be identified as having been a
migrated file. In this way, if the file is restored to a file system or Virtual Volume that has been
configured as Primary storage in a
Data Migration Path , the contents of the file will
automatically be restored to Secondary Storage, leaving a cross-file system link on the Primary
Storage. If the restore target is not part of a Data Migration Path, the file will be restored in its
entirety.
Backups and replications typically copy data from Snapshots that are created when the
operation begins. These Snapshots, however, are only taken on the Primary Storage. As a result,
the backup or replication will retrieve the copy of the migrated file from the live file system on
Secondary Storage. To avoid inconsistencies in the archived data set, migrated files should not
be modified while backups or replications are in progress.
Alternatively, the NDMP environment variable NDMP_BLUEARC_EXCLUDE_MIGRATED can be
used to prevent migrated data from being backed up. This can also be useful if the effective Data
Migration Policies are configured to migrate non-critical files such as music and video files from
home directories or aged data. It can also improve backup and replication time, and isolate the
backup data set to include only the critical information on Primary Storage.
It is important to remember that Data Migrator extends the maximum available capacity of
Primary Storage by migrating data to Secondary Storage. This means that the capacity of the
backup solution, whether tape libraries or a replication target, must also support the new
maximum available capacity. To maintain a reliable backup and recovery system, ensure that
the capacity of the deployed backup solution is at least equal to the combined capacity of
Primary and Secondary Storage. Alternatively, use NDMP_BLUEARC_EXCLUDE_MIGRATED to
isolate the backup dataset to only those files that are hosted natively on Primary Storage.