ZCS Administrator's Guide Network Edition 6.0, Rev 1

Backing up using the Auto-Grouped Method

Configure Auto-Grouped Backup from the CLI

Scheduling Backups

The auto-grouped backup method is configured either from the Admin Console User Interface or from the CLI.

Configure Auto-Grouped Backup from the CLI

Set the backup method in the global configuration, and you can override the configuration on a per server basis if you do not want a server to use the auto-grouped backup method.

To set up auto-grouped backup, you modify LDAP attributes using the zmprov CLI. Type the command as

zmprov mcf <ldap_attribute> <arg>

You can also set the attributes at the server level using zmprov ms.

The following LDAP attributes are modified:

•	zimbraBackupMode. Set it to be Auto-Grouped. The default is Standard.

•	zimbraBackupAutoGroupedInterval. Set this to the interval in either days or weeks that backup sessions should run for a group. The default is 1d. Backup intervals can be 1 or more days, entered as xd (1d); or 1 or more weeks, entered as xw (1w).

•	zimbraBackupAutoGroupedNumGroups. This the number of groups to spread mailboxes over. The default is 7 groups.

Scheduling Backups

The standard backup is the default and is automatically scheduled. To run the auto-grouped backup you must manually configure the backup schedule. Run zmschedulebackup -D to set the default schedule for auto-grouped backups based on your zimbraBackupAutoGroupedInterval setting.

One group is backed up each interval. The auto-grouped backup automatically adjusts for changes in the number of mailboxes on the server. Each backup session backs up the following:

•	All mailboxes that have never been backed up before. These are newly provisioned mailboxes.

•	All mailboxes that have not been backed within the number of scheduled backup days. For example, if backups are scheduled to run over six days, mailboxes that have not been backed up in the past 5 days are backed up.

•	More mailboxes, the oldest backup first. This is done so that the daily auto-grouped backup load is balanced.

Example - if you configured the auto-grouped backup interval to be daily (1d) and the number of groups to be 7, the first time auto-grouped backup runs, all accounts are backed up. After the initial backup, auto-grouped backup runs again the next day. This time accounts that have been newly provisioned and a percentage of accounts close to 1/7 of the total are backed up again, accounts with the oldest backup date are backed up first. This would continue with newly provisioned account and approximately 1/7 of accounts being backed up daily over seven days.

As with the standard backup method, when backing up shared messages, the backup process looks to see whether a file representing a message already exists in the backup. If it does, it flags this object as such and does not copy its content again.

Backup files are saved as zip files without compression. Zipping the backup files saves backup storage space. To change the default zip option, see Appendix A Command Line Interface, zmbackup.

These backup files can be used to restore the complete ZCS system or individual mailboxes so that account and message data is completely restored. Archived redo logs are moved to the backup session as part of the full backup. When the server is restored from an auto-grouped backup, redo logs are replayed to bring the system to the point before the failure.

ZCS Administrator's Guide Network Edition 6.0, Rev 1