HANA Backup fails with "wrong checksum" error

[shaji_narayanan]

Hello HANA experts,

Our HANA (SPS 7) test database system backup ends with following error:

Could not back up system <SID> backup could not be completed, Wrong checksum: Calculated 1320888980, stored 1611380413.; $ppno$=

Error log contents:

145a59295ef ERROR   BACKUP   SAVE DATA finished with error: [447] backup could not be completed, [3020043] Wrong checksum: Calculated 1320888980, stored 1611380413.; $ppno$=

Further details:

Backup failure is for “index server”; backup for rest of the servers gets successfully completed.

How could I resolve this error?  Any help is highly appreciated.

Thanks in advance,

Shaji

[Former Member]

Hello,

did anyone ever find another solution than recovering the last valid backup if this happened on the indexserver datafile? We encounter the same after HANA upgrade from rev. 96 to 97.

The backup right before the upgrade worked, after the upgrade we get the checksum error. There are no I/O errors on the OSlevel and we could not identify any issue with the database.

However, a new backup can not be created. We already opened a call with SAP, but since I am running out of ideas I wonder if anyone has ever fixed this without recovery.

Thank you

Florian

[lbreddemann]

In the vast majority of cases you won't see storage errors when a database reports bad checksums in any of their files.

Think about it: if the I/O system would actually "know" about an error, it would have to return the I/O activity as not ok, which in turn would lead the database to deal with this problem (e.g. retry the I/O, abort the action, report an error).

On top of that, most file-systems don't perform block-wise checksum writing/checking, which means that slight changes in the payload (the database data) won't get noticed.

That's why databases (basically all of them) employ their own checksums.

As you already have a support incident open, you should get the correct guidance in order to resolve this issue.

Concerning the revision upgrade: although it's not impossible I'd say it is very unlikely that this caused the problem. It's very likely just timely co-incidence.

- Lars

[Former Member]

Just to update everyone who is reading this message thread. In the end we found no other solution than performing a recovery to most recent state, which resolved the issue. Since we had to roll through almost 20 days of log-backups and the last valid backup was taken before the upgrade to 97, we first recovered it on a Sandbox for validation before we performed the recovery on the actual system. Regards Florian

[former_member182967]

Hello Shaji,

Check if note 1990971 - HANA backup failed with "Wrong Checksum" error helps?

Regards,

Ning

[Former Member]

what is your backup destination? does it have enough space?

[shaji_narayanan]

Thanks Srithar, backup to disk, enough space available...

[Bockelmann]

Is there any hint? I do have the same problem on my training system.

[Former Member]

See SAP Note 2116157 ("What are typical errors and solutions for corruptions on lower layers?").