LSILogic MegaRAID and "camcontrol: cam_lookup_pass:CAMGETPASSTHRU
ioctl failed"
Scott Long
scottl at samsco.org
Wed Mar 16 15:29:15 PST 2005
Danny Howard wrote:
> Hello,
>
> I have a variety of systems that I inherited, with a variety of hardware
> RAIDs. Most systems are 4.8-4.10. I want to be able to monitor the
> various RAIDs reliably so that I can fix failures faster, but it is a
> bear.
>
> META QUESTION: Can anyone wiser in the ways of SCSI offer a clue? Is
> there a "best practices" approach to monitoring hardware
> RAIDs on FreeBSD? Or suggestions and advice on
> formulating such an approach?
There is no universal way to manage RAID devices, especially between
different vendors. This is something that the big OEMs have been
wishing for for years (I know since I was involved in one of those
failed wishes), but has never happened. Most vendors consider their
management interface to be highly proprietary or non-portable, so
getting source code or specs is practically impossible unless you
have the money to make it worth their while. The only think that
is close to a universal management tool is the atacontrol in FreeBSD
that can configure and monitor several brands of software RAID. This
offers no benefit to your MegaRAID hardware, however.
>
> On a Very Important Machine (VIM) I have:
> amrd0: <LSILogic MegaRAID logical drive> on amr0
> amrd0: 140012MB (286744576 sectors) RAID 5 (optimal)
> SMP: AP CPU #3 Launched!
> pass0 at amr0 bus 0 target 6 lun 0
> pass0: <SUPER GEM359 REV001 1.09> Fixed Processor SCSI-2 device
> Mounting root from ufs:/dev/amrd0s1a
>
> So, I cast about on the net and found amrcontrol at
> http://people.freebsd.org/~emoore/MegaRAID_SCSI/ but it can not see my
> controller when I run it. The VIM is quite new, and amrcontrol is two
> years old, so, this doesn't seem unreasonable.
THe package that you are refering to was a highly experimental and
unsupported porting effort that only had a limited lifetime. I'm
not surprised that is doesn't work. However, LSI is starting to
provide more official FreeBSD support, and it's quite possible that
more appropriate software might be available from their website now.
I haven't checked recently, though, and if it's not there then I can't
answer any questions of when it might be there in the future. Sorry!
>
> I'd be happy just to probe the dmesg part that says:
> amrd0: <LSILogic MegaRAID logical drive> on amr0
> amrd0: 140012MB (286744576 sectors) RAID 5 (optimal)
>
> I take "optimal" to mean "okay" and if it ever said something else, I
> know I have some emergency maintenance to do, and can fail the VIM.
>
> So, I tried camcontrol. I am a little wary of issuing SCSI commands to
> exotic devices because maybe sometimes those devices get an exotic SCSI
> command and freak out? Well, anyways, I try:
The amrd0 devices are NOT scsi devices. They are low-level block
devices that present themselves as disks to the system. The only
thing in your system that camcontrol will be able to talk to is the SES
backplane that was probed (the pass0 device that you mentioned earlier).
Scott
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