On 5/16/19 3:49 PM, Alibek Amaev wrote:
I have more example from IRL:
In Aug 2018 I was start server with attached storages by FC from ZS3
and ZS5 (it is Oracle ZFS Storage Appliance, not NetApp and also
export space as LUN) server use one LUN from ZS5. And recently on
server stopped all IO on this exported LUN and io-wait is grow, in
dmesg no any errors or any changes about FC, no errors in
/var/log/kern.log* /var/log/syslog.log*, no throttling, no edac errors
or other.
But before reboot I saw:
wwn-0x600144f0b49c14d100005b7af8ee001c -> ../../sdc
I try to run partprobe or try to copy from this block device some data
to /dev/null by dd - operations wasn't finished IO is blocked
And after reboot i seen:
wwn-0x600144f0b49c14d100005b7af8ee001c -> ../../sdd
And server is run ok.
Also I have LUN exported from storage in shared mode and it accesible
for all servers by FC. Currently this LUN not need, but now I doubt it
is possible to safely remove it...
It's all a bit conjecture at this point.
'sdc' could be show up as 'sdd' after the next reboot, with no
side-effects whatsoever.
At the same time, 'sdc' could have been blocked by a host of reasons,
none of which are related to the additional device being exported.
It doesn't really look like an issue with device naming; you would need
to do proper investigation on your server to figure out why I/O stopped.
Device renaming is typically the least likely cause here.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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