Data Backup and Recovery

urgent - problem setting begin- and end-backup before snapmirror update (snapcreator)


Hello everybody, i have a little problem using the snapmirror option with snapcreator (Oracle Plugin). If i`m executing the corresponding config-file, two things are executed through snapcreator: 1. a local snapshot will be created, but before this snapshot is done, the begin-backup-mode is set in the oracle database, after the snapshot has finished, end-backup-mode is set --> so everthing is fine and works well 2. after that local snapshot has been done, snapcreator start to do the snapmirror. The problem is, that the snapmirror itself doesn`t set begin- and end-backup-mode to the oracle database, so the data are "only" in a crash consitend state after the data transfer. Do you know, if there is the possibility also to set begin- and end-backup for the snapmirror option in snapcreator? I`m looking forward for every hint. Regards



There is no easy way to put oracle in backup mode around snapmirror but as I explain below there is no reason for this.

Normal SC process for backup w/snapmirror is

1. puts oracle into backup mode

2. snapshot

3. end oracle backup mode and switch logs

4. snapmirror

5. primary snapshot delete

We never put database in backup mode while doing snapmirror, our goal is to transfer snapshots. So yes the snapmirror update is NOT consistent however we dont care about that, what we care about is the snapshots and those are consistent and get transferred Make sense? So goal of snapmirror is to simply transfer the consistent snapshots and since we took snapshot before snapmirror it gets moved to your DR storage and is consistent. The recovery point for oracle would be time of snapshot, from there you could do a roll forward.

Additionally if you have SC 3.5 there is a newer feature which further optimizes Oracle backup. If you have data and logs split into separate volumes (this is of course best practice) then you can use META_DATA_VOLUME=filer:archive_log_volume. This will allow SC to follow following process:

1. oracle in backup mode

2. snapshot data vol

3. oracle end backup mode

4. switch logs

5. snapshot archive log volume

6. snapmirror

7. primary snapshot delete