topic Removing a disk from Raid 1 configuration in ProLiant Servers (ML,DL,SL)

Removing a disk from Raid 1 configuration

Daniel Goldberg_1 — Sun, 22 Aug 2010 11:17:14 GMT

My configuration is :

[root@linux7 ~]# hpacucli ctrl all show config
ls: /sys/bus/scsi/devices/0:0:1:0/: No such file or directory
ls: /sys/bus/scsi/devices/0:0:1:0/: No such file or directory

Smart Array B110i SATA RAID in Slot 0 (Embedded)

array A (SATA, Unused Space: 0 MB)

logicaldrive 1 (149.0 GB, RAID 1, OK)

physicaldrive 1I:1:1 (port 1I:box 1:bay 1, SATA, 160.0 GB, OK)
physicaldrive 2I:1:2 (port 2I:box 1:bay 2, SATA, 160.0 GB, OK)

[root@linux7 ~]#

I want to break the "mirror" I have got by removing the 2nd pd from the logical drive. I am always getting : Error: This operation is not supported with the current configuration. Use the
"show" command on devices to show additional details about the
configuration.
I know that Raid 1 needs a minimum of 2 disks but how can I break the mirror from the OS ?

Re: Removing a disk from Raid 1 configuration

Modris Bremze — Mon, 23 Aug 2010 11:20:24 GMT

What command did you use? Why do you want to remove a drive?

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02289065/c02289065.pdf

Re: Removing a disk from Raid 1 configuration

Daniel Goldberg_1 — Mon, 23 Aug 2010 11:27:25 GMT

I tried running

[root@linux7 ~]# hpacucli ctrl slot=0 array A remove drives=2I:1:2
ls: /sys/bus/scsi/devices/0:0:1:0/: No such file or directory
ls: /sys/bus/scsi/devices/0:0:1:0/: No such file or directory

Error: This operation is not supported with the current configuration. Use the
"show" command on devices to show additional details about the
configuration.

[root@linux7 ~]#

I want to remove the disk so I will have a backup of the system disk before running an upgrade I am about to run.

Re: Removing a disk from Raid 1 configuration

Modris Bremze — Mon, 23 Aug 2010 12:24:35 GMT

I have a suspicion, that removing 1 disk from 2 disk array of RAID 1 will not work as there would not be enough disks left for a legitimate array. You can try deleting an array altogether, however, I don't know if that can be done with the OS running.

If you can reboot the server, it can safely be done with, for example, SmartStart ACU. I think that it would be the safest thing to do in this case.

Re: Removing a disk from Raid 1 configuration

Daniel Goldberg_1 — Tue, 24 Aug 2010 03:17:29 GMT

Well, it is permisable on IBM Blades...I totally understand what you're saying but on other systems it works. What happens if I physically remove one of the 2 disks ? The system won't crash... All I am looking for is a software way for doing it. I don't believe there is no way to do it.
Thanks anyway !!!

Re: Removing a disk from Raid 1 configuration

Modris Bremze — Tue, 24 Aug 2010 10:12:22 GMT

If you yank the second drive out it will work, however the recovery in case something goes wrong with the first disk might get a bit..tricky. Besides the array will not be dissolved by doing this. Once you re-insert the disk it will be re-mirrored from the first one.

Re: Removing a disk from Raid 1 configuration

Daniel Goldberg_1 — Tue, 24 Aug 2010 10:13:58 GMT

Thanks, I am aware of that option but that's not really what I want to do. I want to have the option to do it from the OS with hpacucli.