CentOS - Mar 2016 - Odd behavior of a CentOS 7 box after repair of an external RAID

I don't think I've seen this with CentOS 6 or 5, but I had to repair an
external RAID box this morning. The server, running CentOS 7, has an  LSI
HBA card in it, and it's presented to the system as /dev/sdb. I shut off
the RAID controller, powered it off, did the repair, then plugged
everything back in (that includes the two fiber cables and the ethernet),
and brought the RAID back up. I even used its web page to restart the
controller (in the RAID box.

I couldn't remount the drive until I rebooted the server.

I tried scsi-rescan-bus, and nothing. In the logs, I saw it try to mount
it, then unmount it, and complain that the drive wasn't active.

I was expecting it to act like a hot-swap device. Any clues as to why,
rather than see it removed, it continued to see it as "inactive"?

       mark

On Fri, March 25, 2016 9:55 am, m.roth at 5-cent.us
wrote:
> I don't think I've seen this with CentOS 6 or 5, but I had to
repair an
> external RAID box this morning. The server, running CentOS 7, has an  LSI
> HBA card in it, and it's presented to the system as /dev/sdb. I shut
off
> the RAID controller, powered it off,
You did unmount filesystem on the machine before that, right?
> did the repair, then plugged
> everything back in (that includes the two fiber cables and the ethernet),
> and brought the RAID back up. I even used its web page to restart the
> controller (in the RAID box.
>
> I couldn't remount the drive until I rebooted the server.
Before powering off/disconnecting RAID box, did you remove resembling SCSI
device? this is done if my memory doesn't fail me by doing this:

echo 1 > /sys/class/scsi_device/6:0:0:0/device/delete

(replace "6:0:0:0" with your device's address). If you didn't
remove the
device before powering it off, I'm not surprised. If you did remove the
device before powering it off, I'm puzzled ;-)

Valeri
>
> I tried scsi-rescan-bus, and nothing. In the logs, I saw it try to mount
> it, then unmount it, and complain that the drive wasn't active.
>
> I was expecting it to act like a hot-swap device. Any clues as to why,
> rather than see it removed, it continued to see it as "inactive"?
>
>        mark
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> https://lists.centos.org/mailman/listinfo/centos
>

++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++

Valeri Galtsev wrote:
>
> On Fri, March 25, 2016 9:55 am, m.roth at 5-cent.us wrote:
>> I don't think I've seen this with CentOS 6 or 5, but I had to
repair an
>> external RAID box this morning. The server, running CentOS 7, has an
>> LSI HBA card in it, and it's presented to the system as /dev/sdb.
>> I shut off the RAID controller, powered it off,
>
> You did unmount filesystem on the machine before that, right?
Of course!
>
>> did the repair, then plugged everything back in (that includes the two
>> fiber cables and the ethernet), and brought the RAID back up. I even
>> used its web page to restart the controller (in the RAID box.
>>
>> I couldn't remount the drive until I rebooted the server.
>
> Before powering off/disconnecting RAID box, did you remove resembling SCSI
> device? this is done if my memory doesn't fail me by doing this:
>
> echo 1 > /sys/class/scsi_device/6:0:0:0/device/delete
No - I've never done that. With hot-swap drive bays, the system sees it
going out, and says so, and then the drive goes away, or becomes
inactive... but when I shove one back in, it sees it, though it may make
it as /dev/sd[letter+1] (that is, if it had been /dev/sdb, it's now
/dev/sdc).
>
> (replace "6:0:0:0" with your device's address). If you
didn't remove the
> device before powering it off, I'm not surprised. If you did remove the
> device before powering it off, I'm puzzled ;-)
As I said, I expected the scsi-rescan-bus to clear it up, but though it
saw it, nothing changed.
<snip>
     mark