3.5.2. Automatic Backups
The backup utility watches a pre-determined list of CSN configuration files for file metadata
changes. When a change is detected, the utility waits until the changes stabilize to prevent multiple
incremental backups in a short time period and then creates a gzipped tar file with a complete set of
all designated configuration files. This tar file is staged locally and then written to the storage cluster
for protection. If for any reason, a backup fails to write to DX Storage, an error will be logged and
the backup will be retried periodically. The UUID of the backup set is also written into the Backup
Manifest but is not displayed in the user interface. If the Backup Manifest is not retrievable for any
reason, the backup set is written with metadata that allows retrieval from the DX Storage cluster
using DX Content Router. Specifically, the following two headers will be present:
CAStor-Application-Automatic-Backup: yes
CAStor-Application-Component: saveset
The backup utility will periodically purge backups based on both age and backup count. The utility
will keep at least 20 backups and, if there are more than 20 backups, it will purge any that are more
than 30 days old.
Note
All backup times are displayed in Universal Time (UTC) and may not, therefore,
correspond with the local system clock.
3.5.3. Manual Backups
Administrators may wish to occasionally create a backup manually in conjunction with CSN
maintenance activities (system updates, server downtime, etc). To create a manual backup set at
anytime, click the 'Create Backup' button. You will be prompted to enter a description for the backup
to allow you to easily identify it in the backup list at a later date. The user interface will confirm that
the backup request has been successfully received but cannot display errors if the backup fails
several minutes later. Administrators may wish to monitor system logs for Error messages as a
result. Aside from the manual initiation and description, manual backups are identical to automatic
backups. Manual backups are supported once every 30 seconds.
3.5.4. Restoring a Backup
To restore the service configuration files and enabled/disabled status as they existed as part of a
specific backup set, select the radio button next to the desired backup set and click the 'Restore
Backup' button. This will restore all configuration files and each service's status (enabled or
disabled) to their saved state at the time of the selected backup and reboot the server to reinitialize
the network with the previous configuration. Following a successful reboot, administrators should
immediately restart their DX Storage cluster to ensure the internal networks are aligned and the
node IP addresses are maintained.
After upgrade, previous backup sets may be marked as being compatible with a previous software
version if the backup format or system layout has been changed. These backups cannot be restored
with the current version but will remain available if the software is reverted to a previous version
using the csn-reset functionality.
3.5.5. Failover
If a primary CSN fails, an administrator can choose to promote a secondary CSN to the primary
CSN role by restoring the primary's backup manifest UUID onto the secondary and then restoring
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Version 2.0
December 2010