[CentOS] Odd behavior of a CentOS 7 box after repair of an external RAID

Fri Mar 25 16:36:01 UTC 2016
m.roth at 5-cent.us <m.roth at 5-cent.us>

Valeri Galtsev wrote:
> On Fri, March 25, 2016 10:45 am, m.roth at 5-cent.us wrote:
>> 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,
<snip>
>> 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).
>
> Then we will need real expert to chime in on this...

Yeah, I was wondering about, what, dbus? dracut?
<snip>
>> As I said, I expected the scsi-rescan-bus to clear it up, but though it
>> saw it, nothing changed.
>
> Did you do scsi-rescan-bus after you disconnected the device, and then
> again after you connected it back? I'm just shooting in a dark, but the

No. I didn't think of doing that, because I thought that once I'd shut the
RAID controller down, and powered it off, the system would have noticed.

> first one probably will remove the device that disappeared, and the second
> will add the device back. And it may do nothing about devices that exist

That might have worked; certainly, it's a thought to keep in mind for the
future (he says, pushing it onto the stack).
<snip>
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