Online Backup

[Former Member]

Hi Markus Döhr

I saw your responce for data loss in one of the threads and wanted ask you something.

I had a situation where we lost 2 months data on one of our ECC 6 demo systems.

The databse was backedup couple times after the install. Log writer is switched off.

we had power failure in the room and when we got the system up....We lost 2 monts work.

Its MaxDB 7.6.0.18/ RHEL4 / ECC6.

does MaxDB backup procedure sets DATA VOLUMES to backup mode and stops any updates to data volumes while backing up?

I'm also trying to understand how MaxDB ONLINE Backup works. can you point me to some liks or docs.

Thanks

[former_member229109]

Dear Mr. M.,

-> Please also see the SAP notes::

820824 FAQ: MaxDB/liveCache technology

869267 FAQ: MaxDB LOG area < ! >

< You will find answers on the questions "33. Can I deactivate log writing?"

& " 34. What are the dangers of deactivating log writing?" &

more helpful information ... >

767598 Available documentation

990602 FAQ: CCMS for MaxDB/SAP liveCache technology

1028751 MaxDB/liveCache: New functions in the DBA Cockpit

-> You wrote, that you lost 2 monts work after you had power failure in the room and when you got the system up....

So sorry, but it's not clear for me why.

• Did you get data or log volumes corruption due power failure?

• Did you need to restore the database using databackup which was created 2 month ago ??

• How often are you creating the complete databackups on your system?Incremental databackups?

Please review the recommended "Regular Administration Tasks" at

http://maxdb.sap.com/currentdoc/25/5b27401544ed01e10000000a155106/content.htm

Thank you and best regards, Natalia Khlopina

[Former Member]

Hi All

Many thanks for the input. very helpfull.

Markus

The PDF file u provided was really helpfull and good to know that you are using MaxdB and it is wokin fine.

Natalia Khlopina

Thanks for the help. we did not do any recovery after power failure. After power connection was back we started up the server and did startsap and had no problem. The system came up fine with no problems but the data was lost.

after that experience we backedup everyday.

Thanks

[markus_doehr2]

Hi Markus Döhr

saw your responce for data loss in one of the

threads and wanted ask you something.

had a situation where we lost 2 months data on one

of our ECC 6 demo systems.

he databse was backedup couple times after the

install. Log writer is switched off.

we had power failure in the room and when we got the

system up....We lost 2 monts work.

Its MaxDB 7.6.0.18/ RHEL4 / ECC6.

Hmm.. I would NEVER switch logging off if the system is used productively, where productive is also current development, not just operative business.

does MaxDB backup procedure sets DATA VOLUMES to

backup mode and stops any updates to data volumes

while backing up?

No. The system writes a savepoint (earlier versions used a checkpoint) to flush the data to the disks. After that, the backup starts. During that time, the MaxDB kernel keeps the information, which block has changed since start of the backup internally, so that your backups are always consistent and you can restore them without needing any log (well, never versions do that, with older version you needed to do a "migration save").

A MaxDB backup saves blocks, not "tablespaces" or "volumes". If you do a backup-to-disk, the resulting files don't reflect anything of the actual database file system structure, they can be bigger, smaller, it may be more or less than your actual volumes, they can even have different names. You can then use that backup and restore it into any other database (of the same version and at least the size of the backup).

I'm also trying to understand how MaxDB ONLINE Backup

works. can you point me to some liks or docs.

Conceptually it's not very different to other databases, see e. g.

This is pretty old but you will get the idea.

We run MaxDB now for > 11 years (1,2 TB database) and I'm really happy with it.

--

Markus

[former_member204746]

for docs, check the MaxDB bible at https://www.sdn.sap.com/irj/sdn/maxdb