Lustre devel - Jan 2007 - finding your lustre filesystem

Scenario:  You setup a lustre filesystem (1.6 based) a month ago and things 
work just fine, so you forget about it and lose your notes on it.  Time 
passes, you need to reboot and remount, but can''t remember what the
actual
<filesystem> to mount.

So, other than the obvious "write it down when you make it" answer, is
there a
more inherent way to find the mount?  After some digging, it was suggested 
(thanks Cliff) to look in /proc/fs/lustre/mds (on the mds), which resulted in 
the cryptic:

$ ls /proc/fs/lustre/mds
lustre-MDT0000  num_refs
$

On the off chance that was the answer, trial and error (an old friend) wound 
up showing that "lustre" (without the "-MDT0000") is the
actual filesystem to
mount.  I don''t think I''d have guessed that without help, so
I''m seeking
another solution (or at least a few steps that seem better thought out).  
It''d be nice if there was an equivalent "showmount -e
<lustre>".

-- 
Makia Minich <minich@ornl.gov>
National Center for Computation Science
Oak Ridge National Laboratory

With the latest beta (b7), there are proc files on the MGS showing:
1. all known filesystems
# cat /proc/fs/lustre/mgs/MGS/filesystems
testfs
lustre

2. for each filesystem with at least one running server, the server 
names that participate in that filesystem
# cat /proc/fs/lustre/mgs/MGS/live/testfs
fsname: testfs
flags: 0x0     gen: 4
testfs-MDT0000

# cat /proc/fs/lustre/mgs/MGS/live/lustre
fsname: lustre
flags: 0x0     gen: 16
lustre-MDT0000
lustre-OST0000


For future reference, all servers are named
<fsname>-<MDT|OST><XXXX>
This can be show for live servers under /proc/fs/lustre/devices,
or from the device label at any time:
# e2label /dev/sda
lustre-MDT0000


Makia Minich wrote:
> Scenario:  You setup a lustre filesystem (1.6 based) a month ago and things
> work just fine, so you forget about it and lose your notes on it.  Time 
> passes, you need to reboot and remount, but can''t remember what
the actual
> <filesystem> to mount.
>
> So, other than the obvious "write it down when you make it"
answer, is there a
> more inherent way to find the mount?  After some digging, it was suggested 
> (thanks Cliff) to look in /proc/fs/lustre/mds (on the mds), which resulted
in
> the cryptic:
>
> $ ls /proc/fs/lustre/mds
> lustre-MDT0000  num_refs
> $
>
> On the off chance that was the answer, trial and error (an old friend)
wound
> up showing that "lustre" (without the "-MDT0000") is
the actual filesystem to
> mount.  I don''t think I''d have guessed that without help,
so I''m seeking
> another solution (or at least a few steps that seem better thought out).  
> It''d be nice if there was an equivalent "showmount -e
<lustre>".
>
>