DATA Volume Size

[Former Member]

Hi,

Can i shrink the size of data volume,suppose DB has 3 volumes of 10G each i want o shrink size of volume to 5G & fill level in each volume is only 2 G , is it possible.

I'm on 7.6 build 35. If we delete volume instead of shrinking what happens to data in that volume.

Please let me know. Thanks in advance.

[markus_doehr2 · Accepted solution]

> Can i shrink the size of data volume,suppose DB has 3 volumes of 10G each i want o shrink size of volume to 5G & fill level in each volume is only 2 G , is it possible.

No

> I'm on 7.6 build 35. If we delete volume instead of shrinking what happens to data in that volume.

The data will be moved to the other volumes.

I highly suggest updating your database to a recent service pack and build (7.6.00.35 is VERY old).

Markus

[Former Member · Accepted solution]

Thank you Markus.

Can i delete volume during DB operations, i mean can users access the system during that time.

[lbreddemann · Accepted solution]

> Can i delete volume during DB operations, i mean can users access the system during that time.

Yes (we) you can!

[Former Member · Accepted solution]

can i use database copy to delete volumes, how can i specify(reduce) the no. of volumes on DB during recovery.

Which method is risk free.

Thanks in advance

[lbreddemann · Accepted solution]

>

> can i use database copy to delete volumes, how can i specify(reduce) the no. of volumes on DB during recovery.

Ok, "database copy" is not really a functionality of the MaxDB tools.

Instead, for such a database copy we use the backup/restore functions.

Since we backup pages and not volumes or files you can restore backups into databases with a totally different volume file layout.

As long as the total data area is large enough to contain all backup data (+the converter data) the restore will work.

So it's important to remember that the volume layout is not something that is setup or changed by the restore.

Therefore you have to change the volume layout before you restore the database.

If you create a new instance as a target for the restore, you can just do it while creating the instance.

If you want to reuse an existing instance, you need to reconfigure the instance.

In DBMGUI you can do this via "Instance -> Initialize".

Note: this is not the "Recovery with Initialisation" but a totally different function.

Anyhow, if you just want to change your current data volume setup and don't want to have a downtime - simply follow the approach Markus described.

It's used quite often even and especially for big systems (e.g. from SAP Hosting).

> Which method is risk free.

None of the methods available or discussed here are risky - they are all safe and you won't loose any data by using them.

regards,

Lars