Avamar Server Maintenance Activities

There are server maintenance activities that need to happen daily, which are Garbage Collection (GC), checkpoints and HFS Checking.

Garbage Collection finds orphaned chunks and removes them during the blackout window.  If a backup runs long, GC can not start, and if GC has started then a backup cannot start.  The server goes into read only mode during GC, so restores can complete.  However, if server capacity becomes greater than 85%, any running backups will cancel and GC will automatically run.  GC will normally delete any backup jobs that have been deleted, expired or partial backups that are more than 7 days old.  During the blackout window, Asynchronous Crunching also takes place, which is essentially a defrag-type job for striped data.  It recognizes deleted data and moves other stripes into proximity.

Checkpoints are read only snapshots of the Avamar server, and they enable server rollback in the event of a problem.  They are run twice daily, at the beginning and at the end of the maintenance window.  Avamar will keep the last 2 checkpoints and at least one validated checkpoint.  Checkpoints can be created, modified and executed manually.  The older the checkpoint, the more space they will consume.

Validation is when Avamar scans the stripes and validates the integrity using hfscheck.  The server is read only when the hfscheck is initiated, but then returns to normal operation following.  There is full validation and rolling validation.  Full validation scans all data, while rolling validation scans new data and some modified.  Validation is the bulk of the maintenance window.

Avamar Administrator is used to monitor maintenance activities under the "Server Details" tab.  If maintenance activities are suspended, they will not run until re-enabled by selecting teh maintenance activity and choosing actions -> resume maintenance.  **If maintenance activity is not suspended and not running, contact EMC technical support.

Default schedule for windows:

Backup window runs  at 8:00 PM and runs for 12 hours until 8:00 AM.

Blackout window runs immediately following the backup window and runs for 3 hours, from 8:00 AM to 11;00 AM.  It is mainly running the asynchronous crunching and GC processes.  Backup can not be run during the blackout window, but restores can be run.

The maintenance window runs following the blackout window for the remainder of time until 8:00 PM when the backup window begins again.  It is primarily running HFS checks at that time, and there are a limited number of backups that can be run.  Normally 27 sessions can run, but during maintenance only 3 can be run.  It also takes a checkpoint and validates it.