Auto raid

[Sean Ho]

Recently our group acquired a 9000 machine with an autoraid attached, I did an ioscan found out there are two internal hard disk and 6 LUMs for the autoraid. After further interrogation using diskinfo I found out each of the lum hard disk had a capacity of 7,449 GB and a total of 7.45x6 equal 44.7 GB. However there are 8 phsical disks inside the autoraid (with 4 empty slots), each were labeled 4.3 SE, which gives me total of 4.3x8 equal 34.4 GB. I was baffled by this mismatch, can anyone help me out? thanks.

[A. Clay Stephenson · Accepted solution]

Hi Sean:

You have asked a very complicated question; you just don't know it.

The AutoRAID's automatically switch between RAID 1/0 (for speed) and RAID 5 (for capacity).
At least 10% of the total capacity of the array
stays in RaID 1/0. The idea is that the most recently used data is migrated to the faster RAID 1/0 format. With 8 4.3GB disks and Active Hot Spare ON the maximum capacity is 21.8 GB and with Active Hot Spare OFF it's 25.4GB. The array always has to keep enough space to cover the failure on the largest single drive. You can mix & match drives within the enclosure as well. The usable space can be divided among a maximum of 8 LUN's which can be any size you choose. You can't point to any drive or drives and say that LUN3 is there because LUN3 is spread over all the drives. Diskinfo simply reports the size of whatever you set the LUN to.

The commands which are used to display and manage the array are arraydsp and arraymgr. Man arraydsp and arraymgr for details. If you are new to this, this easiest method is to use SAM to set your array up.

Externally you AutoRAID usually has 2 HVD SCSI buses which are then split into 4 internal SE-SCSI buses.

That should at least get you started; now go find your AutoRAID manuals.

Regards, Clay

[linuxfan]

Hi Sean,

Well what you are seeing is actually true. With 8 (4.3 disks) you actually have 24 GB of usable disk space, but you must be having dual paths to the autoraid (alternate links) thats why the total is adding up to double of the actual space available.

Here is a link to find out the Autoraid's usable disk capacity tool
http://www.hp.com/essd/capacity.html

Here is a manual for Managing Autoraid 12H
http://www.hp.com/cposupport/manual_set/lpg28365.pdf

Someother useful links
http://www.hp.com/cposupport/manindex/hpsurestor19162_eng_man.html

http://www.hp.com/products1/storage/disk_arrays/midrange/12h/index.html


Some of the commonly used commands
arraydsp -i
(gives the serial number of the array)
arraydsp -a
(gives the whole configuration of the array)
arraycfg
(for creating new LUNS)

Most of the array commands are in /opt/hparray/bin, so look at their man pages. Also check out the docs.

-HTH
Ramesh

[linuxfan]

Hi Sean,

you said, you have 6 LUNS configured (each of 7.45 GB)? but the actual number of disks are 8(4.3GB) hmm...

can you post the output of ioscan -kfnC disk and arraydsp -a?

-Regards
Ramesh

[Sean Ho]

Hi Clay,
Thanks for your quick response, You're right I'm only on this job for 4 months and just completed the first HP-UX Sys. Adm class. I think I'll get the manual soon since we'll upgrade the system from 10 to 11 very soon. With members like your capacity and willing to help in this forum I'm convinced this is the right place for me to find answers and remove my anxiety caused by work. Thanks again

Regards,
Sean

[Sean Ho]

Hi Ramesh,
Thanks for your precious info, as my previous reply indicated I'll definitely have more questions in the future, your answer will be highly apprecited.

Regards,
Sean

[Adrian Horne]

Hi

If this an AutoRAID that has been passed to you, I would also check that the firmware on the controllers is at a reasonable version.

With some of the older firmware it was possible to lose all data on the AutoRAID.