change number of data file

[Former Member]

I need to copy the data files to a SAN and want to change the number of data files form 4 to 1. This is only a small database (22Gb). I don't know how to delete the data files and re create them.

Regards

Hans

[Former Member · Accepted solution]

Hi Roland,

i don't want to upgrade the database yet. I presume that the db_activate etc only can be done via dbmcli commands? Where can I find the syntax and doco for the order to follow?

regards

Hans

[roland_mallmann · Accepted solution]

Hi Hans,

no, you can also do it using DBMGUI. The process is really the same as when you're doing a homogenous system copy, the only difference is the target itself is the same db instance.

You'd have to make sure you've backup up all (data+log) and no further data was created (for example by making a full data backup in ADMIN mode and saving the log). Then you'd need to initialize the DB and specify the desired number of (data) volumes and make sure you select the radio button labelled 'Create instance for recovery' during the initialization process, so the instance will only be put into ADMIN, after which you can then recover (using the backups made in the beginning).

I'd recommend to test this out yourself on a small (non production) db instance.

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In comparison, from MaxDB version 7.6.00 Build 22 onwards, you would just have deleted the unwanted volumes (taking into respect that the left over volume can hold all data).

Regards,

Roland

[Former Member]

Hi Roland,

I am running MaxDB version 7.5.00.42 with DBMGUI version 7.6.00.25

which of the 2 options should I use?

Can I perform these actions throught the GUI or do I need the dbmcli commands?

[roland_mallmann]

Hi Hans,

with your used MaxDB version, you only have the second opportunity really. This would involve making a full data backup of the current system, then recreate (db_activate/init config + recover) the instance with only a single volume.

The only other possibility would be to upgrade to 7.6. I would recommend the latest 7.6.03 version in that case.

Regards,

Roland

[roland_mallmann]

Hi Hans,

depending on your used MaxDB version, you can either:

a) drop the volumes using the <a href="http://dev.mysql.com/doc/maxdb/en/a6/e57f423c278951e10000000a1550b0/content.htm">'db_deletevolume'</a> dbmcli command or

b) recreate the DB with a single volume (init config / db_activate + recovery)

Regards,

Roland