IOseq error after activating the DR/standby database

[Former Member]

Hi

We are testing our DR strategy on out QA ECC Instance. When we failed over the database successfully start but we received the following errors when we tried to perform a LOG backup:

ERR 20031 Log Free logpages failed: Free IOSeqRange 6998959...7008465 but OldstNotSaved=6998958

We stopped the database (nicely) but when we tried to restart the database we got the following error and the database was put into OFFLINE.

ERR -24778 DBMSrv -9209, System Error: KB Log error

ERR -24778 DBMSrv 20002,Expected ioseq 6998958, found 6998959-6998959 on off 1

ERR -24778 DBMSrv 20022,OldestNotSaved not found on log

We are running 7.6.04.16 and we have built the DR system as follows (using a perl script with the maxdb perl libraries):

db_connect

db_activate RECOVER medium DATA

recover_start medium LOG 300

recover_replace medium e:\logs 301

recover_replace medium e:\logs 302

<loop which performs a recover_replace using the next log file in the sequence>

...

The logs are copied from the source system once it is confirmed the SRC log backup is complete. The script then applies the copied log using the recover_replace.

When we are ready to activate the DR database when stop the script (nicely) and put the database online manually.

Do I need to put a recover_cancel before the recovery session is closed?

Am I missing an extra step that needs to be performed before I can activate the database?

[lbreddemann · Accepted solution]

Hi Doug,

is the failover database instance running in logmode OVERWRITE?

Sounds like you face the issue from sap note #1345139 - Log is not released after backup.

I suggest that after the failover you take a complete data backup and run the steps described in the note to clear the log area.

Alternatively you may just install the current 7.6.06 patch to have the fix for this bug in your installation.

regards,

Lars

[Former Member · Accepted solution]

HI Lars

The DR system is not in OVERWRITE mode.

The note, 1345139, is not available to me and maybe only released internally at SAP.

Is there a work around mentioned or steps I should follow?

We are going to upgrade to 7.6.6 once we have completed applying the Service Packs to our ECC landscape.

Regards

Doug

PS: Thanks for your assistance with the high priority call a few weeks back

[markus_doehr2 · Accepted solution]

I vaguely remember a bug that was present quite some time ago - where, at the time a log backup was taken manually (so not triggered because the segment was full), that the last page in the log area was not written to the disk if it was not completely filled (means, if e. g. only 4 kb were in that page and not the full 8 kb).

However, this is quite some time ago, I may be wrong.

Markus

[lbreddemann · Accepted solution]

> The note, 1345139, is not available to me and maybe only released internally at SAP.

Sorry - I oversaw that. (once there actually is a internal note and then this happens ...

> Is there a work around mentioned or steps I should follow?

Yes, there is a workaround.

And it is described in the note.

Now, the reason for why this note is internal is that the workaround is a potential risky procedure, that can lead to data loss when used falsely.

We don't want to see people thinking "oh, fine, let's try this!" without beeing 100% sure what they are doing.

So I cannot put this workaround out here.

But simply open a support message and refer to this sdn thread and the note and I'm sure that my colleagues will give the workaround to you.

> PS: Thanks for your assistance with the high priority call a few weeks back

You're welcome ... (if I only could remember which message it was... )

regards,

Lars

[Former Member · Accepted solution]

Hi Lars

Thanks for the information.

One other question, does the note mention whether the issue would be resolved if we upgrade to 7.6.6.*??

Thanks

Doug

[lbreddemann · Accepted solution]

> One other question, does the note mention whether the issue would be resolved if we upgrade to 7.6.6.*??

>

Yes, it does - with 7.6.06 the problem should not reoccur.( -> PTS 1161432, 1161433.)

regards,

Lars