Topic: How can I tell if my hardware raid is working properly

[markdeblois]

Hi there,

Sorry for my newbie questions (I entered this question in a existing post a few days ago but go response. Your kind help is greatly appreciated!)

I have bought a Dell PowerEdge SC1430 server with 2 raid 1 disks (250Gb). I was planning to install SME Server with a software raid but the machine came with a hardware raid (SAS 5iR U320 SAS Controller). Installation went fine and it works well.

What I am not sure of is whether the raid was configured correctly automatically. In the server-manager menu Disk Redundancy it tells me that it might be using hardware mirroring, which I believe is the case. But whether this is actually working I am not sure. I would greatly appreciate your help!

If I try: cat /proc/mdstat , I get

Personalities : [raid1]
md1 : active raid1 sda1[0]
104320 blocks [2/1] [U_]

md2 : active raid1 sda2[0]
243055296 blocks [2/1] [U_]

unused devices: <none>

The result of fdisk -l is:

Disk /dev/sda: 248.9 GB, 248999051264 bytes
255 heads, 63 sectors/track, 30272 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 fd Linux raid autodetect
/dev/sda2 14 30272 243055417+ fd Linux raid autodetect

Disk /dev/md2: 248.8 GB, 248888623104 bytes
2 heads, 4 sectors/track, 60763824 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


Disk /dev/md1: 106 MB, 106823680 bytes
2 heads, 4 sectors/track, 26080 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


And if I try mdadm --detail /dev/md2 I get:
/dev/md2:
Version : 00.90.01
Creation Time : Fri Apr 6 02:48:56 2007
Raid Level : raid1
Array Size : 243055296 (231.80 GiB 248.89 GB)
Device Size : 243055296 (231.80 GiB 248.89 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 2
Persistence : Superblock is persistent

Update Time : Mon May 7 23:22:30 2007
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0


Number Major Minor RaidDevice State
0 8 2 0 active sync /dev/sda2
1 0 0 -1 removed
UUID : 212b400a:2e501081:36defda4:6d35900e
Events : 0.46590

I am not 100% sure how to interpret this information. Thanks so much for pointing me in the right direction!

cheers,
Mark

[idyll]

I also run a DELL with hardware RAID (a PowerEdge 850), and I use the Dell-provided utility which provides a web GUI to the innards of the DELL-provided hardware RAID configuration and monitoring.

I am sure you can finesse this using the command line but don't see why you should bother when a GUI can be used.

DELL has multiple flavors of their utility called Open Manage, based upon the specific age of your hardware. As CentoOS is RH derived, the utilities work fine in most cases.

Poke around DELL's site and you can find the freebie downloads, which may have dependencies of course. My RAID is the PERC4 SC U320 unit and the GUI software provides all I need.

regards,
patrick

[markdeblois]

Hi idyll,

Thanks for the advice, I was unaware of this utility. I tried installing it off the cd that came with the system, but then it prompts me to wipe out my current installation. Is it necessary to install this utility first and then the SME Server OS?!

Regards,
Mark

[idyll]

No, you do not need to install Open Manage first.

I was able to install it using a package I found on a DELL CD I had. It is Open manage 5.1.2 and the whole thing is ~ 400mb. If you can somehow copy it to disk and install it using the command line you should be OK.

Perhaps using the CD, per say, is where you are having troubles?

regards,

patrick

[markdeblois]

Hi Patrick,

Thanks for your help. I am in quite unfamiliar terrirtory here, as you can probably tell.
I am indeed not finding the file on the cd. Is it a rpm package that I need? And should I be using RH4 or RH5 stuff?!
I did come across this link which mentions OMSA CentOS installation can be done through yum. Does this look like a solution to you?

http://linux.dell.com/repo/hardware/#yum

I tried this and it seems that it has added Dell hardware to the list of sources, but nevertheless it tells me that it can't find the Dell packages (no match for argument). I could probably download the right packages but I am not sure which I need. I upgraded yum to 2.4.3 but that was not the problem apparantly.

Thanks again for your help.

cheers,
Mark