topic Re: Increasing disk space by stopping mirroring in Disk Enclosures

Increasing disk space by stopping mirroring

hingray — Fri, 04 Mar 2005 04:27:51 GMT

I have got a Proliant 5500 Xeon with smart array 3200. 4 disk 9,1 G for multidisk A Raid 0+1 and 2 disk 18,2G for multidisk B Raid 1.
My Os is NT4.0 SP6 and I must upgrade in W2k
System partition C: is 1,5Go on Disk 0, Notes/data partition are agregat partition on Disk 0 and Disk 1. 2,3 G at the end of Disk 1 are free.
Before Upgrading I'd like to have more space on C: and I dont't know if I can do it by changing Raid 0+1 to Raid 0. What will append if I do that ? What will I see in windows, more space in C: or simply free space on disk 0 ?

Thank all in advance

Re: Increasing disk space by stopping mirroring

Karl Rohwedder — Fri, 04 Mar 2005 04:48:56 GMT

Normally the reconfiguration of a raid array from e.g. 0+1 to 0 or 5 looses all data, so a complete and reliable backup before is mandatory.
If you go from 0+1 to 0, you loose all reliability and the failure probability will increase dramatically, because failure of 1 disk out of you 4 disks then will destroy your array.

Perhaps you could use tools such as Partition Magic et.al. to move your partitions to the end using the free 2.3 GB and then expand the C partition. Note: I would recommend a backup before doing this also.

mfg Kalle

Re: Increasing disk space by stopping mirroring

Uwe Zessin — Fri, 04 Mar 2005 04:57:53 GMT

Certain Smart Array controllers have the ability to (slowly) change the RAID level online. If the SA3200 can do that in your situation, I cannot tell.

If it works, you will *not* automatically have more free space on the logical disk for C:. You will rather see free space at the end of the disk array. Next step would be to extend the logical disk. Assuming this works, too, you will *still* won't have free space on C:, because the partition table is not updated.

That's when the partition management that Karl mentions comes into play. I fully agree with his suggestion that you make sure you have a very good backup before you start. This type of work has a high potential to destroy all your data. Good luck!

Re: Increasing disk space by stopping mirroring

hingray — Fri, 04 Mar 2005 05:16:07 GMT

Thank you a lot,
So, to maintain reliability, I think it would be better to use the 2,3 Go free space but it is at the end of the other logical disk Disk1.
Is partitionmagic able to do the work between 2 logical disks ? Will NT4.0 start again with C partition at the end ?
And what about W2k upgrading on such partition ?
Thank you again
Regis

Re: Increasing disk space by stopping mirroring

e4services — Sat, 05 Mar 2005 09:45:03 GMT

You will need the partition manager for servers to do this. or just start up a new OS partition with new disks (seems simplier than upgrading)