[Lustre-discuss] Beginners Question: Mapping Lustre Node <-> DNS Hostname?

[Andreas Dilger]

On Mar 31, 2009  10:20 -0400, Brian J. Murrell wrote:
> On Tue, 2009-03-31 at 13:38 +0200, Wolfgang Stief wrote:
> > with the corresponding IP hostname/domain
> > (something like lussrv1.some.domain)?
> 
> I guess what you really want to know is "what is the IP address (and by
> extension, DNS name) of the machine that is currently providing the
> testfs-OST0001 target?".
> 
> But again, the answer is not so simply an IP address as IP is only one
> of several networking protocols that Lustre works on and as such it
> (LNET) does not use IP addresses as node identifiers but uses NIDs
> instead.  For some protocols, the NID does use the IP address, but this
> is just a convenience of that given protocol.  So really, the only thing
> you can really ask is "what NID is serving the target testfs-OST0001?".
> 
> I'm afraid I don't think there is any easy way to ask this currently,
> other than brute-force searching through the OSSes.

You can use:

$ lctl get_param osc.${fsname}-${OSTname}*.ost_conn_uuid

e.g.

$ lctl get_param osc.*-OST0000*.ost_conn_uuid
osc.myth-OST0000-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp

or
$ lctl get_param osc.*.ost_conn_uuid
osc.myth-OST0000-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp
osc.myth-OST0001-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp
osc.myth-OST0002-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp
osc.myth-OST0003-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp
osc.myth-OST0004-osc-f1579000.ost_conn_uuid=192.168.20.1 at tcp

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.