the 'lshowmount' command on the servers can do this.

However I sometimes have seen where lshowmount doesn't show any connected clients, but they obviously still are. So maybe there's a lower-level way than that utility that's better.

Scott

On 7/6/2015 10:09 AM, Jérôme BECOT wrote:

That's how i proceed, but i had kernel crashes on the MDS so I unmounted
and remounted it and it recovers

No way to check wether Lustre servers considers any client still connect
or not ?

Le 04/07/2015 04:43, Kurt Strosahl a écrit :

Hi,

    I just did a clean shutdown/startup of two lustre file systems
last weekend (also for electrical work).  The order that I've found
most effective is to first shutdown all the clients, then unmount the
osts/shutdown the oss systems, then unmount the mdt/mgs and shut down
that system.  On the up I've found that turning on the mdt/mgs system,
letting it mount up.  Then mounting the osts (my oss systems don't
mount lustre on boot).  Once the last ost to be mounted looks like it
has finished any recovery it needs to do I mount a single client and
make sure it can see the entire system... and then go from there with
the rest of the clients.

Since all the lustre clients I have are in the same room as the lustre
file system itself I don't have to check for stray mounts (I just walk
around the room looking for systems that are still on, and then power
them off).

Good luck,
Kurt J. Strosahl
System Administrator
Scientific Computing Group, Thomas Jefferson National Accelerator
Facility


Message: 1
Date: Fri, 03 Jul 2015 13:49:32 +0200
From: J?r?me BECOT <jerome.becot@inserm.fr>
To: HPDD-discuss@ml01.01.org
Subject: [HPDD-discuss] Clean shutdown
Message-ID: <559676CC.1060009@inserm.fr>
Content-Type: text/plain; charset=utf-8; format=flowed

Hi there,

We are running a small lustre system (1MGS/MDS + 2 OSTs). I haven't
found the information, so i ask you :

What is the good order to shutdown the whole system (for electrical
maintenance ...) when you run a combined MGT/MDT :
- disconnect the clients
- is there any way to check if there is a client still connected ?
- unmount the MGT/MDT
- unmount the OSTs
- ... poweroff all the servers
- mount the OSTs
- then the MGT/MDT
- then the clients ?

or should I stop the ost first and mount them last ?

Thanks

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