Yet another RAID Question (YARQ)

[P.U.Kruppa]

On Sun, 19 Jun 2005, Alex Zbyslaw wrote:

> P.U.Kruppa wrote:
>
>> our school has just received a new HP ProLiant and I set up FreeBSD 5.4 
>> -RELEASE with a RAID 1 system on it (using ciss driver).
>> Is there any software tool which can show me the state of the two SCSI 
>> discs (if one is failing or if they are mirrored sorrectly) or is it 
>> sufficient to watch the little LEDs on the box?
>
> That's a good question, and I only have a partial answer for you.  You can 
> look at sysutils/smartmontools port which will show you the SMART status for 
> the disks that it can see.  If you can see both disks (which I *think* would 
> have devices like /dev/sd0, /dev/sd1) then you ought to know if the disks are 
> failing.  SCSI disks, from my limited experience, don't show as much info as 
> ATA disks, but so far both Quantum and Fujitsu do seem to have supported 
> SMART at a basic level.  You should be able to tell what FreeBSD can see in 
> the way of disks by examining /var/run/dmesg.boot.
>
> A word of caution, though.  A Linux system (which I help administer) had two 
> SCSI disks mounted as RAID-1 through some kind of Adaptec controller. 
> Recently the machine crashed and it transpires that one of the disks hadn't 
> been written to since 2002!  I am told that the bootup screen showed the 
> RAID-1 as working, and Linux could *only* see one virtual disk -- the 
> supposed RAID mirror.  So, I think your question is a very good one!  We had 
> (apparently) no way of knowing what was going on. The machine crashed with no 
> messages whatsoever, after losing all access to its disks, and there was no 
> indication that RAID-1 was not functioning.
>
> I *think* that the RAID controller should spot when a disk is failing and 
> notify you (through its driver) through console messages and 
> /var/log/messages.  I too would love an answer to this question for any 
> decent SCSI controller under FreeBSD (e.g. Dell PowerEdge 2850 with PERC 
> 4e/Di RAID controller).  Can you, in general, see through the RAID controller 
> to monitor individual disks?
No, the HP manual says one can check the disks via some sort of 
LED blinking code. But I have no experience with that, since it 
is a new machine.

Uli.

>
> --Alex
>
>



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* Peter Ulrich Kruppa - Wuppertal - Germany * 
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