If recovery to the data backup point, the backup catalog is needed?

[Former Member]

Hi eveyone,

I'm designing backup and recovery with the following conditions;

- The RPO is the data backup poin.

- HANA system is set up for system replication, and the log mode is 'normal', because it's a prerequisite of system replication.

So, the bakcup log files are not needed and I delete.

How about the backup catalog?

If I recover to the data backup point, the backup catalog is needed?

regards,

Noriko

[deepak_chodha · Accepted solution]

Hi Noriko,

Now it depends where you are doing all these things: setting of log mode/deletion of log backups depends upon if you are doing it in Prod or QA/DEV HANA systems.

1. Are you trying to recovery of primary site?
2. What do you mean by data backup point? Point in time recovery or just the recovery with complete database backup?

Happy HANA, Deepak.

[Former Member · Accepted solution]

Hi Deepak,

Yes, I'm trying to recover of primary system.

The business requirements;

  RPO is the complete data backup point. 

  It means that I don't need to recover to the point in time before the error.

  Backup log files are not needed.

The situation;

  A is the primary system.

  B is the secondary system.

  I setup system replication between A and B.

I'm designing;

  I perform complete data backup daily, and delete backup log files daily.

  If disks are broken on the primary system , the primary system is down, and the backup catalog is lost.

  For saving time to recover, I recover with complete data backup.

  If I take over to B, initiate full replication will be done after A is back.

  It leads long recovery time.

  Because RPO is the complete data backup point, I don't take over to B and only recover with complete data backup.

As above , the backup catalog is lost.

Can I revcober with complete data backup only?

regards,

Noriko

[deepak_chodha · Accepted solution]

Hi Noriko,

In simple words in recovery to your scenario you don't need backup catalog.

But talking about "If I take over to B, initiate full replication will be done after A is back. It leads long recovery time." I think your understanding needs to be changed. What you are trying to do will not at all make use of system replication then why having it!

Once A is back full shipping will not be problem still because ideally you 0 RTO compared to RTO>0 in backup recovery. Above all compared to backup and recovery, system replication will give you much better performance, least RTO and RPO.

Happy HANA, Deepak.

[Former Member · Accepted solution]

Hi Deepak,

Thanks.

I see;
- I don't need backup catalog for recoverying with complete data backup.

- System Replication performance will be better than backup and recovery.

I can design  in more detail.

Thanks again,

Noriko

[Former Member]

Hi Noriko,

Backup Catalog is keeping a track of all backup transactions and it includes both data and log backups. The backup catalog is written to the same path as the log backup files(you must be already aware)

Now it is very important to have the backup catalog handy during the recovery as all the information for the restore is available in this, so do not delete this file

I understand your RPO is last Data backup point, but I would recommend to retain the Log backups and have them copied to tape as they can help you go further and recover the system upto a point in time(you never know when the business requirements change and update the RPO)

[Former Member]

Hi Sunil,

As my reply to Deepak, RPO is the complete data backup point.  

It means that I don't need to recover to the point in time before the error.

If disks are broken, the backup catalog is lost too.

Can I recover with complete data bakcup only?

If No, I need to backup the backup catalog to another storage.

regards,

Noriko

[Former Member]

Please note Backuo Catalog is keeping a track of all the Data and log backup information for a HANA System

If you loose the backup catalog you must be able to identfy the right Data backup to which you would like to recover, if you have this information you can do a recovery, you should not need the backup catalog(I have not tested this but I am quite sure it would not complain)

The next option to find the backup details would be the backup.log, here you will find entries for each backup operation on a HANA instance

Hope this answers your question