Question about backup

[Former Member]

I just did a few backup to DISK test of SAP HANA using hdbstudio.

It seems like there are 4 channels. 

e.g.

1 channel for  nameserver volume 

1 channel for indexserver volume 

1 channel for statisticsserver  volume

1 channel for   xsengine volume

I could see that indexserver having data segments and log segments that need to be backup.( because its actual db data )

But what could possibly be stored in nameserver volume ? that requires a data segment and log segment as well …?

( from backup perspective )

From backup perspective what kind of data are we backing up on Name server and statistics server and xsengine ?

I thought only indexserver persist data.  I guess I am wrong.

Can someone elaborate more on this ?

I read the backup and recovery guide , it does not specify what kind of data we backup on nameserver and statisticsserver and xsengine.

It only says anything that persist data would get backup. ( But what is it ?)

[Former Member · Accepted solution]

Hi Power,

Names server stores the topology information of the database and also what components running, it will have more data on multi node HANA. XS engine data volume stores all the web service components and other app related packages and stats server has the database state information. These all information are stored in meta data tables and it keeps growing with the changes on the database.

All these data is needed for the database to be recovered successfully with the backup and make database operational if you need to recover anytime.

Thanks

Suresh

[Former Member · Accepted solution]

Thank you so much Suresh , for clarifying this.

This is where I got stucked,  I thought only the index server store information in the database. The rest of the services store information "separate" from the database ( which is not True).   Since all other services store information in db table segment , it makes sense to synchronize between those tables and backup all of them.

I hope they would clarify this on the Backup and Recovery Guide !!!

[swapan_saha]

Hello,

I see this is generic HANA question is posted here under HANA One community. If the information is not available in public documents (check out http://help.sap.com/hana) or from your help inbuilt within HANA Studio, it is less likely the information requested will be available here in this community only. This is not an answer to your question but its a comment only.

Thanks,

Swapan