Catalog Recovery through AIR

[Amit_Karia]

Hi All,

I recently checked AIR feature for replicating de-duplicated data to DR site, however today i spoke with Symantec support. I suggested about catalog replication and do a tape less DR catalog recovery rather than building Catalog through DR Image file

What are everyone's views on this?

[SymTerry]

The NetBackup high availability guide (DOC5183) states:

The Auto Image Replication feature allows backups to be duplicated between the

NetBackup domains and it automatically creates the catalog entries in the target

domain as the backups are duplicated. Symantec recommends the use of Auto

Image Replication instead of live catalog replication as a means of populating the

NetBackup catalog at a disaster recovery site.

So Air replicates backups, not the catalog itself. Once the backup has been replicated to the DR site, every 60 seconds, a image fragment process is kicked off on the DR Master server that creates an entry in the catalog on the DR site. 

Now lets say your production Master server takes a dive. You have one of 2 options for restore:

• Use your DR site to create a catalog DR file that you then use to do a cataolg recovery on the producation side.
• Use reverse AIR (TECH205923). This solution is only supported for Symantec's PureDisk storage type.

With all of that being said, the HA guide but it also says:

Catalog replication does not remove the requirement for catalog backup.

Regularly back up the NetBackup catalog from the primary master server to

protect against accidental image expiration or other inconsistencies that are

introduced in the catalog on the primary site and replicated to the secondary

site.

Hope this helps

[Marianne]

I agree with Terry.

AIR was never meant for Catalog replication. It replicates the backups and updates master server with relevant catalog entries.
This means that there is no need for catalog recovery. Catalogs are already updated. Simply start restores.

One more thing - remote master is independent.
Different hostname and could possibly have own clients and media servers.
You cannot recover source master server because of different identities.

[MortenSeeberg]

Disagree.

If you are sending only important backups from master1 to master2 domain via AIR, there may still be a need one day to recover master1 if it is lost one day.

Backing up master1 via AIR means you can automate the catalog backup to another site, I consider testing actually replicating the catalog backup to another master and then try to recover the primary master from that backup.

[Mark_Solutions]

Catalog replication via AIR is supported these days as long as source and target master are on exactly the same version of NetBackup (otherwise the replication works but the import fails)

In my experince it has been used when only one site has access to tape so that the second site can import the catalog backup and then duplicate it to tape

Really not sure that i would want to use it on the DR site when that is already setup as a master in its own right - it does seem failrly pointless to me ot be honest - though of course totally possible with the proper planning and preparation

Just don't fancy the idea as the primary beauty of AIR was to remove the need or a catalog recovery etc. and to give immediate restore capabilities from a DR site.

[MortenSeeberg]

You misunderstand (or I wrote in a confusion way :) ), I want to use the AIR catalog copy sent to master2, to recover master1 (the original source), not to recover the master receiving the copy.

This is useful for customers with only 2 sites using AIR to the opposite, site, but they still might want to recover their catalog on the primary site if something goes wrong.