RE: datafiles on NFS?

Kevin,

I have spoken with our netapp admins, and what they told me the following:

When you are changing db blocks for the first time since the latest snapshot was taken, the snapshot size will increase. This snapshot space is (at first) consumed within the snapshot reserve of your volume (which is typically set to 20% of your volume space). This snapshot reserve space is not available for the active file system, but when the snapshots grow larger then the snapshot reserve space they will start to consume space from the active file system.

What probably happened is that due to the growth of the filesystem and the snapshots, both the snapshot reserve and the active filesystem became full, after which updates on existing db blocks would fail (as the snapshot could no longer grow).

If you are unlucky this could indeed cause oracle to get corrupted as writes to an existing db block will fail.

A possible solution would be to implement file reservation (which would cause netapp to reserve 100% of the file size for further updates). Or allow the volume to auto grow or to auto delete snapshots.

Regards,  

Freek D'Hooge
Uptime
Oracle Database Administrator
email: freek.dhooge_at_uptime.be
tel +32(0)3 451 23 82
http://www.uptime.be
disclaimer

-----Original Message-----

From: Lange, Kevin [mailto:KLange_at_ppoone.com] Sent: woensdag 12 maart 2008 18:58
To: D'Hooge Freek; ORACLE-L
Subject: RE: datafiles on NFS?

I am not sure how to lookup the version of ON-TAP we are using but when getting the VERSION from the netapp I get

NetApp Release 7.0.6

If there is something else, just send the syntax

-----Original Message-----

From: D'Hooge Freek [mailto:Freek.DHooge_at_uptime.be] Sent: Wednesday, March 12, 2008 12:02 PM To: Lange, Kevin; ORACLE-L
Subject: RE: datafiles on NFS?

Kevin,

Yep, that's the correct setting.

Makes the corruption very strange.
Could you pass me the ontap version? I will check with our netapp admin if he has ever heard of this.

Regards,

Freek D'Hooge
Uptime
Oracle Database Administrator
email: freek.dhooge_at_uptime.be
tel +32(0)3 451 23 82
http://www.uptime.be
disclaimer

-----Original Message-----

From: Lange, Kevin [mailto:KLange_at_ppoone.com] Sent: woensdag 12 maart 2008 17:19
To: D'Hooge Freek; ORACLE-L
Subject: RE: datafiles on NFS?

The value each value for this says

guarantee=volume

Is that the correct setting to be using ?

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