[ovirt-users] NFS and pass discards\unmap question

[Nir Soffer]

On Fri, Feb 3, 2017 at 2:29 PM, Sergey Kulikov <serg_k at msm.ru> wrote:
>
>
> Hm... maybe I need to set any options, is there any way to force ovirt to mount with this extension, or version 4.2
> there is only 4.1 selection in "New Domain" menu.
> Current mount options:
> type nfs4 (rw,relatime,vers=4.1,rsize=65536,wsize=65536,namlen=255,soft,nosharecache,proto=tcp,port=0,timeo=600,retrans=6,sec=sys,local_lock=none)
>
> it should work only if forced option vers=4.2 ?
> I thought it's implemented as feature to older version, not 4.2, there is few info about this.

Looks like ovirt engine does not allow nfs version 4.2.

We have this RFE:
https://bugzilla.redhat.com/1406398

So practically, both sparsify and pass discard with NFS are useless
in the current version.

I think this should be fix for next 4.1 build.

Nir

>
>
> --
>
>
>
>  Friday, February 3, 2017, 14:45:43:
>
>
>
>
>
>> On Thu, Feb 2, 2017 at 11:45 PM, Sergey Kulikov <serg_k at msm.ru> wrote:
>
>
>>  I've upgraded to 4.1 release, it have great feature "Pass
>> discards", that now can be used without vdsm hooks,
>>  After upgrade I've tested it with NFS 4.1 storage, exported from
>> netapp, but unfortunately found out, that
>>  it's not working, after some investigation, I've found, that NFS
>> implementation(even 4.1) in Centos 7
>>  doesn't support sparse files and fallocate(FALLOC_FL_PUNCH_HOLE),
>> that quemu uses for file storage, it was
>>  added only in kernel 3.18, and sparse files is also announced feature of upcoming NFS4.2,
>>  sparsify also not working on this data domains(runs, but nothing happens).
>>
>>  This test also shows, that FALLOC_FL_PUNCH_HOLE not working, it
>> was executed on centos ovirt host with mounted nfs share:
>>  # truncate -s 1024 test1
>>  # fallocate -p -o 0 -l 1024 test1
>>  fallocate: keep size mode (-n option) unsupported
>>
>>  Is there any plans to backport this feature to node-ng, or centos? or we should wait for RHEL 8?
>
>
>
>
>> Interesting, I was under the impression it was fixed some time ago,
>> for 7.2[1] (kernel-3.10.0-313.el7)
>> Perhaps you are not mounted with 4.2?
>
>
>> Y.
>> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1079385
>>
>>  NFS is more and more popular, so discards is VERY useful feature.
>>  I'm also planning to test fallocate on latest fedora with 4.x kernel and mounted nfs.
>>
>>  Thanks for your work!
>>
>>  --
>>
>>  _______________________________________________
>>  Users mailing list
>>  Users at ovirt.org
>>  http://lists.ovirt.org/mailman/listinfo/users
>>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users