topic Re: Breaking a mirror in Disk Enclosures

Breaking a mirror

Mark_397 — Thu, 11 Dec 2003 10:26:23 GMT

Hi, hopefully an easy one. I have a DL380 with two disks that are configured as a mirrored pair. The machine is now being used for development rather than being live, so I am more interested in disk space than resilience. If I modify the configuration to break the mirror, am I going to loose the data thats on the disks now? Or will I (hopefully) just end up with another disk for me to assign a drive letter and fill with data?
Thanks in advance, Mark

Re: Breaking a mirror

Massimo Bianchi — Thu, 11 Dec 2003 10:49:55 GMT

Hi,
if you mean software mirroring, made with LVM, you will retain your data.

you have to issue, for each mirrored lvol, the command:

lvextend -m 0 /dev/vgXX/lvolYY

The mirror will be deleted, and the space gained almost immediatly.

HTH,
Massimo

Re: Breaking a mirror

Mark_397 — Thu, 11 Dec 2003 11:50:01 GMT

Thanks for getting back to me. I did not mean mirroring using the microsoft disk manager interface. In this interface the two disks appear as one disk (with several logical drives within it), not as a mirrored pair. I meant mirroring using the compaq array configuration utility / smart array controller. I guess (but please correct me if I am wrong) you did not mean this with your suggestion.
Mark

Re: Breaking a mirror

Kevin Harlan — Thu, 11 Dec 2003 12:50:30 GMT

Yes, if you go into ACU and change your array, you will lose your data.

I don't remember what array controllers had what capabilities (i.e. if you're using a DL380G1 then you have a ROC controller, if you're using a G2 then you have a SmartArray 5i), but some arrays have the ability to "migrate" array types.

If you can migrate your RAID array from a RAID 1 to a RAID 0, then you would get to keep your data intact as well as gain back the "extra" disk space.

If you cannot, then I don't know of any way other than a backup and restore. Backup your data, change your RAID array, then restore.

Re: Breaking a mirror

Massimo Bianchi — Fri, 12 Dec 2003 03:39:19 GMT

Hi,
first time i got i wrong, i thought that you had a unix server (D380).

With the microsoft DL380, the oncly chance i know is backup / restore....

Massimo

Re: Breaking a mirror

Mark_397 — Fri, 12 Dec 2003 08:41:06 GMT

There was a migration option, and I now have lots of lovely disk space to fill. Thanks for that guys, much appreciated. :)