RAID 5 configuration

[Carlos23]

Hi all,


I need to configure a RAID 5 in a Superdome system that have 2 system disk with 3 disk of 36GB with HPUX 11v2, help me please.

Thank´s.

[Patrick Wallek]

It can't be done at the software level.

LVM does not support software RAID 5.

VxVM, the base software that comes with HP-UX does not support it either. I **think** the FULL version of VxVM, which you would have to upgrade to either through HP or Veritas, supports software RAID5.

[Hein van den Heuvel]

Nobody 'needs' RAID-5.
Some of use are forced to use it.
If you do 'need' to go there be sure to use a HARDWARE controller with WRITE CACHE to implement it.

And if your really 'need' to do this, then please use more than 3 disk.
The disk savings with only 3 disks are minimal (2 effective out of 3) and the (performance) price is maximum compared to simple RAID 0+1 ( 1 1/2 disk effective out of 3).

(Not all controllers know how to do raid 0+1 with an odd number of disks, but it can be done)

fwiw,
Hein.

[John_Hancock]

Agree with all of the above. Beg, borrow or steal an additional 36 G and use mirror-UX to create distributed/mirrored to give you 72G of space.

It may be a posibility of mirroring two disks and using the third unmirrored for stuff you dont mind loosing. Depending on the disk usage the may be a lot of rubbish you can throw oin the single disk. Just a thought.

I have not used raid 5 in so long I cannot remember.

[Jaime Bolanos Rojas.]

Carlos,

If you really need your RAID 5 in your Superdome, then make sure that you have a Raid Controller on the server, or go with one of the following options,

http://www.hp.com/products1/serverconnectivity/storagesnf2/raid160/specifications/index.html

Regards,

Jaime.

[florin_10]

Hi Carlos,

In order to configure a RAID 5 a minimum 3 disks are needed. HP offers the h/w neccesary for RAID 5 or 6 implementation.
You need:
I - a RAID controler ie. HP SmartArrayCardControle 6402(two channels) or 6404(4 channels) series, SCSI ULTRA320
II - a MSA30 disk enclosure
III - and of course a minimum 3 disks to populate the enclosure.

The controler card comes with the utilities(sautil, saconfig) neccesary to configure the RAID then using the LVM create the new vgs and the rest.

Regards,
Florin

[florin_10]

Hi Carlos23,

How are you going with the RAID configuration?
Cheers,
Flg