Array Conf

[aziz_1]

Hi,
My customer ask me a array configuration with RAID 5, that can withstand the loss of 2 disk mech. he still access 100 % of his data.
I propose 2 Lun RAID5.
what's your reflection ?
Thks

[Victor BERRIDGE · Accepted solution]

Hi,
I dont see how in RAID5 you could achieve this exept by mirroring 2 arrays (but you cant call this raid5) or having 2 arrays with a spare per array but again 2 disks loss on the same array and youre dead...
Only you have to remember that such a case is highly improbable unless you havent noticed the loss of the first disk that happened some time ago...

Regards
Victor

[Victor BERRIDGE]

Hi,
I forgot to add:
You should use 2 connections whatever you do in order to be controller redundant (alternate links)
Best regards
Victor

[Thomas J. Harrold]

Hi Aziz,

If you want redundancy, then raid 1+0 (raid 10) is what
you should convince your client to use. Performance will be significantly better as well!

If you have to use raid5 (usually to keep the number of disks down to save money), then consider using at least one hot spare per array. If you can use two hot spare devices per disk tray, that would be even better.

No matter what raid level you choose, have multiple paths from your host to your raid controller.

Best of luck,

-tjh