Re: [Problem]NFS Server – Umount results in Device Busy.

[Namjae Jeon <linkinjeon@gmail.com>]

2012/6/7, Boaz Harrosh <bharrosh@panasas.com>:
> On 06/07/2012 12:43 PM, Namjae Jeon wrote:
>
>> 2012/6/7, Boaz Harrosh <bharrosh@panasas.com>:
>>> On 06/07/2012 10:47 AM, Namjae Jeon wrote:
>>>
>>>> Hi Bruce, Trond.
>>>>
>>>> As you know, Currently umount results in busy on NFS server although
>>>> user tried to succeed to umount on NFS client.
>>>> I suggest to add umount procedure to avoid umount busy issue.
>>>> When calling umount on NFS client, The resources(exportfs entries
>>>> cache) of mount point will be flushed on NFS server. and umount will
>>>> be succeed without busy issue.
>>>>
>>>> how do you think about this suggestion ?
>>>>
>>>
>>>
>>> I second this request, what is needed so when all clients unmounted,
>>> the system comes back to the sate it was before any clients have
>>> mounted. i.e filesystems is not referenced and may unmount cleanly.
>>> (This also happens with >= 4.0 clients only, so no excuses)
>>>
>>> This is a real problem for me, on Fedora machines. Because I export
>>> iscsi devices which are network devices, and in the shutdown procedure
>>> for some reason the "service nfs stop" of the server is much much to
>>> late. the original umount of exofs (-o _netdev) fails because it's
>>> held by NFSD, the iscsi devices go away regardless, and when nfsd
>>> finally releases exofs, it gets deadlocked on some error handling.
>>> OK I know I must fix the stuck-ness, but the problem will remain.
>>> The FS will not unmount cleanly because it will only attempt
>>> an unmount after its devices are gone. This will be solved if
>>> nfsd would release its hold on the FS when all clients are gone.
>>>
>>> It was on my TODO to fix this for a long time, but I seem to be
>>> too busy with more urgent matters. (What's the point of fixing the
>>> shutdown if the steady state doesn't work yet)
>>>
>>> If someone has investigated the matter and knows what to do I would
>>> appreciate any insights, and/or patches would be wonderful ;-)
>> Hi Boaz.
>> Oh.. You also are facing same problem.
>> Actually I almost finish to imprement the patch about umount busy
>> issue on NFS server. But I want to know Maintainer's opinion before
>> posting.
>> Thanks.
>
>
> Please post it (maybe as RFC) I want to see it
Okay, I will soon.
>
> Thanks
> Boaz
>
>>>
>>>> Thanks.
>>>>
>>>
>>> <>
>>>
>>> Thanks
>>> Boaz
>>>
>>>
>
>
>