Question Re: Manually Trigger HANA Log Backup in Technology Q&A

Manually Trigger HANA Log Backup

Former Member — Fri, 05 Sep 2014 01:34:37 GMT

Hello experts,

I want to know that if there is any method to manually trigger HANA log backup (not just wait it full and time out to let it backup)

Thanks & Best Regards,

Tong Ning

Re: Manually Trigger HANA Log Backup

lbreddemann — Sun, 07 Sep 2014 16:02:11 GMT

Why would you want to do this?

And yes, technically possible but not supported through any documented interface.

There's no use case for that.

- Lars

Re: Manually Trigger HANA Log Backup

Former Member — Sun, 07 Sep 2014 17:32:22 GMT

Hi Tong,

I think we are really lucky that log backup can be taken automatically .

Make the log_backup_timeout_s--Less than 300 seconds..It will force the log backup at a fixed time interval before the log segment is full.

Regards,

Joydeep.

Re: Manually Trigger HANA Log Backup

Former Member — Tue, 09 Sep 2014 01:33:08 GMT

Hello Lars,

For example like Oracle database, I want to manually trigger a log backup to test if backup to the third backup software can be successfully...

Yeah, I also can't find this information in HANA doc.

Thanks & Best Regards,

Tong Ning

Re: Manually Trigger HANA Log Backup

lbreddemann — Tue, 09 Sep 2014 07:09:01 GMT

And there is your error ... right there ... "... like Oracle database ..."

Seriously: even on Oracle there hadn't been a need to manually trigger log backups in order to be able to fully recover since RMAN had been introduced many, many years ago.

But that's a different story.

For SAP HANA in order to be able to recover you don't need log backups.

Whenever you take a data backup, it will contain the consistent snapshot of the database like it was when the backup started.

- Lars

Re: Manually Trigger HANA Log Backup

Former Member — Tue, 09 Sep 2014 07:17:15 GMT

Hello Lars,

Still, thanks a lot for your detailed explanation.

Best Regards,

Tong Ning

Re: Manually Trigger HANA Log Backup

Former Member — Thu, 11 Sep 2014 17:24:50 GMT

Lars,

If log backup is not required in HANA,can you please let us know how you will perform the point in time recovery?Also recovery just before the database crashed?

Re: Manually Trigger HANA Log Backup

lbreddemann — Thu, 11 Sep 2014 18:24:46 GMT

Hey Joydeep,

who's 'us'?

The 'us' that doesn't read the admin. guide?

Or the 'us' that reads more into my replies than what's really in them?

I wrote that no manual triggering of the log backup is required.

Nothing more, nothing less.

The typical use case for triggering log backups on Oracle was to perform what the BRTOOLS called a 'consistent backup'. If you just copied the Oracle data files away, the contents was inconsistent and a recovery was absolutely required to use this backup.

And this exact use case is simply not given with SAP HANA.

SAP HANA (just like MaxDB) always creates data backups that could be used without any log backups.

- Lars

Re: Manually Trigger HANA Log Backup

Former Member — Fri, 12 Sep 2014 20:17:45 GMT

Lars,

I would suggest to check your own thread once more..

What you have written: For SAP HANA in order to be able to recover you don't need log backups..

Do you think your above statement is correct?If so then please let ME know how I will perform the point in time recovery?Also recovery just before the database crashed without a log backup?

Regards,

Joydeep.

Re: Manually Trigger HANA Log Backup

lbreddemann — Sat, 13 Sep 2014 07:13:11 GMT

Seriously?

You want to pick a single sentence out of a complete reply and discuss this?

Well, go ahead as I won't.

Can you recover a SAP database backup without additional log backups? Yes, absolutely.

That's the point.

Did I write anything about all the different recovery scenarios that may apply? Nope.

Did I imply that generally SAP HANA doesn't use log backups to be enable inter-data-backup recovery? Nope, again.

Besides that: recovery to "just before the database crashed" is typically not done based on log backups but instead based on the most recent snapshot in the data volumes and the log information in the log volumes - the log backups are not required for that.

- Lars

Re: Manually Trigger HANA Log Backup

Former Member — Tue, 16 Sep 2014 21:28:19 GMT

Lars,

I picked up your sentence as the statement is contardiction to HA-200 Certification Guide-Section(Recovery)..

(A) Recover the database to its most recent state:

This option recovers the database to as close as possible to the current time.

This recovery option uses the following data:

• The most recent data backup

• Log backups made since the most recent data backup

• Log area

If Log backups are not required for Recovering the database to its most recent state:
then why SAP is saying that in certification guide?

Regards,

Joydeep

Re: Manually Trigger HANA Log Backup

Former Member — Tue, 16 Sep 2014 22:44:24 GMT

You misread what Lars wrote.

A full data backup is consistent.

Log backups are required for point in time recovery to a time past the last full data backup.

That's all there is to it.

Re: Manually Trigger HANA Log Backup

Former Member — Sat, 08 Jun 2019 05:09:20 GMT

Refer to note 2222218 - FAQ: SAP HANA Database Server Management Console (hdbcons), use log backup command.