Recommended backup strategy for SAP JAVA unclear.

[Former Member]

Hi,

The recommended backup strategy for a SAP JAVA system (with or without ABAP) is unclear to me. Especially the online backup raises questions. I have found the following statements of SAP:

- online backup is officially supported for all SAP NetWeaver components as of NW04, SP10 (SAP-note 779708).

- online backup does not guarantee a full and consistent backup of all system components (SAP library, Backing Up and Restoring AS Java: http://help.sap.com/saphelp_nw70/helpdata/en/ec/9e1802dd600947abafd2248518697f/frameset.htm)

- online database backup must be made in conjunction with an online filesystem backup of /usr/sap/<SID>. To ensure that no changes are made to the file system during backup, stop the Software Deployment Manager (SDM). (same link as previous).

- In most cases, backing up just the database shared by the portal and SAP Web Application Server is sufficient. (SAP Library, Portal Backup and Restore Strategy, same link as previous)

The current landscape I am responsible for consists of an PI, EP and a solution manager landscape. All systems have (ABAP+) Java stacks and are distributed systems, so the databases and SAP application servers reside on different hosts. Making an offline backup of these systems is no problem. Simply stop the SAP system, backup the database offline, start the SAP system. In case of a restore, these elements can be restored and started together with a filesystem restore if needed.

But now the online backup. Just backing up the database is in most cases sufficient, so SAP says. This is to vague to be sure in my opinion. I can't tell a customer that the restore is not working because 'in this case' the backup was not sufficient... For on online backup, /usr/sap/<SID> must be backed up as well. This implies that the database MUST be consistent with filesystem /usr/sap/<SID> to be sure a restore can be carried out succesfully. In other words, just backing up the database is NOT enough for an online scenario. But now imagine the following scenario: an online backup has been made tuesday 23:00 together with /usr/sap/<SID> with an offline SDM as SAP states. On thursday 18:00 (or any time later than the backup) the system crashes and must be restored for whatever reason. The OS filesystem will be restored first if necessary and after that the database and /usr/sap/<SID>. System succesfully restored with status tuesday 23:00. But the database can be further restored by applying the database logfiles to status thursday 17:00. A normal strategy from a database point of view and used very often for a SAP ABAP only system by example. But in case of a JAVA system, this procedure cannot apply, since the filesystem is not further restored, but still has status tuesday 18:00. Off course, I would try it any way and if the system runs ok, mission accomplished. But in fact this cannot be a valid backup strategy, it contradicts with the condition that the database must be consistent with the filesystem.

So how would a valid strategy look like then?

- Only make offline backups just to be sure? >>> not acceptable for systems that need high availability.

- When online backups must be restored, only restore the backup and do not apply database logfiles? >>> not acceptable because dataloss is guaranteed.

- Apart from making online backups, additionally stop the SDM regularly (every hour for example) and make a incremental FS backup?. In case of a restore, restore point-in-time with the database logfiles to the time the SDM was shut down and the incremental FS backup was made? >>> needless to say, this requires a lot of configuration, work and becomes too complex in my opinion.

- etc?

I'm sure some of you think I'm splitting hairs here, but I think SAP simply is unclear when it comes to this AND see if the splitting hair argument is relevant when thinks are not working in case of a restore :-).

Regards,

GJK

[Former Member]

Hai,

When online backups must be restored, only restore the backup and do not apply database logfiles? >>> not acceptable because dataloss is guaranteed. -

---

>Yes,Try the online_consistent backup instead of online backup

http://help.sap.com/saphelp_45b/helpdata/en/0d/d305f54a0c11d182b80000e829fbfe/content.htm

incremental FS backup was made? >>> needless to say, this requires a lot of configuration, work and becomes too complex in my opinion.

etc?----

---

> Yes, if one of the Incremental backup fails,there is loss of data

SAP had given different options for the backups to use according to the requirements.

Thanks and Regards,

[Former Member]

Hi,

I'm facing having the same confusionn , does any one have a startigy or procedure for backup/restore portal with ESS & MSS are deployed on it.

Best Regards,

Sh..

[former_member188806]

Hi,

I'm stuck with precisely the same reasoning.

An offline backupusr/sap/SIDsystem state backup should be sufficient ..right?

The online backup would be too risky in case of a restore..

Thanks,

Saba.