RAID group in AutoRaid (12H)

[Rui Vilao]

Greetings,

I have 3 K servers connected to an AutoRaid (12H).
I read that the performance of these arrays is different if they work in
RAID group 0, 0/1 or 5. The one which assures the best for performance and
redundancy is 0/1.

How can check the RAID of each the defined LUNs? Is it possible to pre-define
a working RAID group (eg. 0/1)?

Thanks in advance for your help,

Kind Regards,

Rui.

[Rick Garland]

The arraydsp and arraycfg commands will provide you with the info you are looking for.

[Patrick Wessel · Accepted solution]

Rui,
The advantage of the AutoRAID is, that it's decides on it's own if it can operate in Raid 0/1 (better performance) or Raid 5 (less space). The array transfers large amount of data which isn't used for a while automaticly to Raid 5. You are not able to pre-define a Raid level. The only influence you have is by increasing the diskspace.
Check out what arraydsp can do for you in displaying the LUN information, or http://www.hp.com/essd/model12H_documentation.html for documentation about the array

[Lothar Krueler]

Hi Rui,
it isn`t possible to configure a autoraid 12H LUN to a raid level. The 12H does it automatically by itsself, depending on the allocated space by LUNs. If the overall allocated space is less or eaqual than half of the total disccapacity, the 12h will use raid 0/1. If the overall allocated space is more, the 12H will begin using raid level 5. First with less used data. The difficulty is, that you can?t say this LUN runs raid 0/1 and that LUN runs raid 5. Annother problem is, if it has been running in raid 5 and you increase discspace, you can`t trust the 12H in changeing back to raid 0/1. It might be nescassary to clear and restore several LUNs.
That`s what I learned by opening a call at HP when I had this problem.
Lothar