Working with Synthetic Full Backup

The following information addresses common questions about how Synthetic Full Backup works.

What types of agents does Synthetic Full Backup support?

Synthetic Full Backup only supports r17.5 or higher Windows Client Agents. It does not support Windows Client Agents prior to r17.5, database agents, or application agents.

Note: To perform synthetic full backup jobs, you must install and license Arcserve Backup Agent for Open Files on the computers that you want to back up.

What backup methods can be submitted with the Synthetic Full Backup option?

You can submit three types of backup with Synthetic Full Backup:

What types of devices does Synthetic Full Backup support?

Synthetic Full Backup supports Disk-staging devices and Deduplication devices. However, you can migrate the Synthetic Full Backup session to Tape, Cloud, and FSD with D2D2T.

Does a Synthetic Full Backup job let you back up the supported and unsupported agents?

Yes. Although Synthetic Full Backup only supports r17.5 or higher Windows Client Agents, you still can submit a Synthetic Full Backup job to back up the mixed sources. The mixed sources include the r17.5 or higher Windows Client Agent, Windows Client Agents prior to r17.5, database agents, or application agents. When you submit a Synthetic Full Backup job that contains mixed sources, it only synthesizes the r17.5 or higher Windows Client Agents. For the agents and application agents that do not support Synthetic Full Backup, the traditional backup method will be used instead (the backup method for those unsupported agents does not change).

What is the daily backup method for the mixed Synthetic Full Backup job for one week?

Assume you submit a Synthetic Full Backup with the 5-day weekly incremental backup, full backup on Friday scheme to back up an 18.0 Windows Client Agent, an r17 Windows Client Agent, and a SQL 2008 agent together on Monday.

Here is the daily backup method for the agent for one week:

Monday

Tuesday

Wednesday

Thursday

Friday

18.0 Windows Client Agent

Full

Incremental

Incremental

Incremental

Incremental + Synthetic Full Backup

r17 Windows Client Agent

Full

Incremental

Incremental

Incremental

Full

SQL 2008 Agent

Full

Incremental

Incremental

Incremental

Full

When I select the GFS scheme, the synthetic schedule is disabled. When will the data synthetic job launch?

For the Synthetic Full Backup job with GFS scheme, the data synthetic job will be launched on the full backup day. For example, if you choose the 5-day incremental backup, Full backup on Friday with GFS enabled scheme, the data synthetic job will be launched on every Friday. If you choose the 7-day incremental backup, Full backup on Sunday with GFS enabled scheme, the data synthetic job will be launched on every Sunday.

What is the purge policy of a Synthetic Full Backup job?

If you submit a Synthetic Full Backup job with enable staging, there are two purge policies; one is for the migration policy, and the other is for the synthetic policy. For staging a Synthetic Full Backup job, the sessions related to synthetic on a staging device are purged according to the Synthetic Purge Policy. The sessions not related to synthetic on a staging device are purged according to the Migration Purge Policy.

For a Normal Deduplication synthetic job, the sessions related to synthetic on a Deduplication device are purged according to the Synthetic Purge Policy. The sessions not related to synthetic on a Deduplication device are purged according to purge configuration in the Deduplication Policy.

Note: You can calculate the Synthetic Purge Policy with the following formula:

MAX (MIN (Synthetic Cycle Time * 2, Real Full Cycle Time), Session Retain Time in Purge Policy)

When is a real full backup job run?

A real full backup is launched in any of the following conditions: