Valdis wrote:
Keep in mind that if you have multiple NSD servers in the cluster, there
is *no* guarantee that the names for a device will be consistent across
the servers, or across reboots. And when multipath is involved, you may
have 4 or 8 or even more names for the same device....
Indeed the is whole greatness about NSDs (and in passing why Lustre can be
much more tricky to safely manage.)
Once a lun is "labelled" as an NSD then that NSD name is all you need to
care about as the /dev entries can now freely change on reboot or differ across
nodes. Indeed if you connect an arbitrary node to an NSD disk via a SAN cable,
gpfs will recognise it and use it as a shortcut to that lun.
Finally recall that in the NSD stanza file the /dev entry is only matched
for on the first of the listed NSD servers; the other NSD servers will discover
and learn which NSD this is, ignoring the /dev value in this stanza.
Daniel
IBM Spectrum Storage Software
+44 (0)7818 522266
Sent from my iPad using IBM Verse
On 17 Dec 2016, 21:43:00, [email protected] wrote:
From: [email protected]
To: [email protected]
Cc:
Date: 17 Dec 2016 21:43:00
Subject: Re: [gpfsug-discuss] translating /dev device into nsd name
On Fri, 16 Dec 2016 23:24:34 -0500, Aaron Knister said:
> that I can then parse and map the nsd id to the nsd name. I hesitate
> calling ts* commands directly and I admit it's perhaps an irrational
> fear, but I associate the -D flag with "delete" in my head and am afraid
> that some day -D may be just that and *poof* there go my NSD descriptors.
Others have mentioned mmlsdnsd -m and -X
Keep in mind that if you have multiple NSD servers in the cluster, there
is *no* guarantee that the names for a device will be consistent across
the servers, or across reboots. And when multipath is involved, you may
have 4 or 8 or even more names for the same device....
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