converting hot spare disks into usable disks

[JOHN TURNER_2]

Is there a way of converting hot spare disks in an FC60 array into usable disks. We are not concerned with hot spare disks, as it's only a test array and there is no real need for redundancy

[Bernhard Mueller · Accepted solution]

John,

it is
ammgr -d

Regards,
Bernhard

[JOHN TURNER_2]

Bernhard as you seem to know a great deal about this, what would be the best way of reutilising these disks, as we now have 4 x 18gb disks free and would like to re-use them as we are runnnig out of space within the array

[Bernhard Mueller]

John,

with 4x 18GB disks I would in most cases recommend creating a RAID5 LUN which would yield about 50 GB usable space *and* you could still survive a single disk failure.
(if that happens, you can decide to backup and restore somewhere else or replace the disk)

If you need all the space and don't care about a potentially lengthy disruption if a disk goes bad you could create a RAID0 LUN of almost 70GB. It's up to you. I assume you have seen in the other thread, that you need to have controller firmware HP08 at least for creating a RAID0 LUN.

Regards,
Bernhard

[JOHN TURNER_2]

cheers,

i have now managed to created a 50gb LUN using 4 disks and raid level 5, however i don't seem to be able to use this lun and create some extra space in the volume group, that we want to extend, can anyone shed some light on the situation

[Bernhard Mueller]

John,

well you did not mention you wanted to extend a VG, then you most certainly hit any LVM limit, if you do not plan ahead...

most likely your existing VG was built using smaller PVs, which determined the "max pe per pv" setting. hence you cannot add a larger disk (or lun or PV) to that VG.

anyway, easiest way out is to just create a new VG, with new Lvols and filesystems, if you need to extend a certain filesystem, you may either copy it over to the new VG and then remove the old one, or you have to create smaller LUNs that you can add to the existing VG (if you have not reached "max pv per VG" etc etc

Regards,
Bernhard