[Gluster-users] Slow write times to gluster disk

Pat Haley phaley at mit.edu
Fri Jul 14 01:10:17 UTC 2017


Hi Soumya,

I just noticed some of the notes at the bottom.  In particular

  * Till glusterfs-3.7, gluster-NFS (gNFS) gets enabled by default. The
    only requirement is that kernel-NFS has to be disabled for
    gluster-NFS to come up. Please disable kernel-NFS server and restart
    glusterd to start gNFS. In case of any issues with starting gNFS
    server, please look at /var/log/glusterfs/nfs.log.

If we disable the kernel-NFS on our server and restart glusterd to start 
gNFS will that affect the NFS file system also being served by that 
server (i.e. the single server serves both a glusterFS area and an NFS  
area)?  Would we also have to disable the kernel-NFS for NFS-ganesha?

My second question concerns NFS-ganesha (v 2.3.x) for CentOS 6.8 and 
gluster 3.7.11.  I think I see a couple of possibilities

 1. I see one possible rpm for version 2.3.3 in
    https://mirror.chpc.utah.edu/pub/vault.centos.org/centos/6.8/storage/Source/gluster-3.8/
    The other rpm's seem to be for gluster 3.8 packages, so I'm
    wondering if there is a concern for conflict
 2. In one of the links you sent
    (https://buildlogs.centos.org/centos/6/storage/x86_64/gluster-3.7/)
    I see an rpm for glusterfs-ganesha-3.7.11 .  Is this a specific
    gluster package for compatibility with ganesha or a ganesha package
    for gluster?

Does either possibility seem more likely to be what I need than the other?

Pat


On 07/07/2017 01:31 PM, Soumya Koduri wrote:
> Hi,
>
> On 07/07/2017 06:16 AM, Pat Haley wrote:
>>
>> Hi All,
>>
>> A follow-up question.  I've been looking at various pages on nfs-ganesha
>> & gluster.  Is there a version of nfs-ganesha that is recommended for
>> use with
>>
>> glusterfs 3.7.11 built on Apr 27 2016 14:09:22
>> CentOS release 6.8 (Final)
>
> For glusterfs 3.7, nfs-ganesha-2.3-* version can be used.
>
> I see the packages built in centos7 storage sig [1] but not for 
> centos6. Request Niels to comment.
>
>
>>
>> Thanks
>>
>> Pat
>>
>>
>> On 07/05/2017 11:36 AM, Pat Haley wrote:
>>>
>>> Hi Soumya,
>>>
>>> (1) In http://mseas.mit.edu/download/phaley/GlusterUsers/TestNFSmount/
>>> I've placed the following 2 log files
>>>
>>> etc-glusterfs-glusterd.vol.log
>>> gdata.log
>>>
>>> The first has repeated messages about nfs disconnects.  The second had
>>> the <fuse_mnt_direcotry>.log name (but not much information).
>>>
>
> Hmm yeah..weird ..there are not much logs in fuse mnt log file.
>
>>> (2) About the gluster-NFS native server:  do you know where we can
>>> find documentation on how to use/install it?  We haven't had success
>>> in our searches.
>>>
>
> Till glusterfs-3.7, gluster-NFS (gNFS) gets enabled by default. The 
> only requirement is that kernel-NFS has to be disabled for gluster-NFS 
> to come up. Please disable kernel-NFS server and restart glusterd to 
> start gNFS. In case of any issues with starting gNFS server, please 
> look at /var/log/glusterfs/nfs.log.
>
> Thanks,
> Soumya
>
>
> [1] https://buildlogs.centos.org/centos/7/storage/x86_64/gluster-3.7/
> [2] https://buildlogs.centos.org/centos/6/storage/x86_64/gluster-3.7/
>
>>> Thanks
>>>
>>> Pat
>>>
>>>
>>> On 07/04/2017 05:01 AM, Soumya Koduri wrote:
>>>>
>>>>
>>>> On 07/03/2017 09:01 PM, Pat Haley wrote:
>>>>>
>>>>> Hi Soumya,
>>>>>
>>>>> When I originally did the tests I ran tcpdump on the client.
>>>>>
>>>>> I have rerun the tests, doing tcpdump on the server
>>>>>
>>>>> tcpdump -i any -nnSs 0 host 172.16.1.121 -w 
>>>>> /root/capture_nfsfail.pcap
>>>>>
>>>>> The results are in the same place
>>>>>
>>>>> http://mseas.mit.edu/download/phaley/GlusterUsers/TestNFSmount/
>>>>>
>>>>> capture_nfsfail.pcap   has the results from the failed touch 
>>>>> experiment
>>>>> capture_nfssucceed.pcap  has the results from the successful touch
>>>>> experiment
>>>>>
>>>>> The brick log files are there too.
>>>>
>>>> Thanks for sharing. Looks like the error is not generated
>>>> @gluster-server side. The permission denied error was caused by
>>>> either kNFS or by fuse-mnt process or probably by the combination.
>>>>
>>>> To check fuse-mnt logs, please look at
>>>> /var/log/glusterfs/<fuse_mnt_direcotry>.log
>>>>
>>>> For eg.: if you have fuse mounted the gluster volume at /mnt/fuse-mnt
>>>> and exported it via kNFS, the log location for that fuse_mnt shall be
>>>> at /var/log/glusterfs/mnt-fuse-mnt.log
>>>>
>>>>
>>>> Also why not switch to either gluster-NFS native server or
>>>> NFS-Ganesha instead of using kNFS, as they are recommended NFS
>>>> servers to use with gluster?
>>>>
>>>> Thanks,
>>>> Soumya
>>>>
>>>>>
>>>>> I believe we are using kernel-NFS exporting a fuse mounted gluster
>>>>> volume.  I am having Steve confirm this.  I tried to find the 
>>>>> fuse-mnt
>>>>> logs but failed.  Where should I look for them?
>>>>>
>>>>> Thanks
>>>>>
>>>>> Pat
>>>>>
>>>>>
>>>>>
>>>>> On 07/03/2017 07:58 AM, Soumya Koduri wrote:
>>>>>>
>>>>>>
>>>>>> On 06/30/2017 07:56 PM, Pat Haley wrote:
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> I was wondering if there were any additional test we could 
>>>>>>> perform to
>>>>>>> help debug the group write-permissions issue?
>>>>>>
>>>>>> Sorry for the delay. Please find response inline --
>>>>>>
>>>>>>>
>>>>>>> Thanks
>>>>>>>
>>>>>>> Pat
>>>>>>>
>>>>>>>
>>>>>>> On 06/27/2017 12:29 PM, Pat Haley wrote:
>>>>>>>>
>>>>>>>> Hi Soumya,
>>>>>>>>
>>>>>>>> One example, we have a common working directory dri_fleat in the
>>>>>>>> gluster volume
>>>>>>>>
>>>>>>>> drwxrwsr-x 22 root dri_fleat     4.0K May  1 15:14 dri_fleat
>>>>>>>>
>>>>>>>> my user (phaley) does not own that directory but is a member of 
>>>>>>>> the
>>>>>>>> group  dri_fleat and should have write permissions. When I go 
>>>>>>>> to the
>>>>>>>> nfs-mounted version and try to use the touch command I get the
>>>>>>>> following
>>>>>>>>
>>>>>>>> ibfdr-compute-0-4(dri_fleat)% touch dum
>>>>>>>> touch: cannot touch `dum': Permission denied
>>>>>>>>
>>>>>>>> One of the sub-directories under dri_fleat is "test" which phaley
>>>>>>>> owns
>>>>>>>>
>>>>>>>> drwxrwsr-x  2 phaley   dri_fleat 4.0K May  1 15:16 test
>>>>>>>>
>>>>>>>> Under this directory (mounted via nfs) user phaley can write
>>>>>>>>
>>>>>>>> ibfdr-compute-0-4(test)% touch dum
>>>>>>>> ibfdr-compute-0-4(test)%
>>>>>>>>
>>>>>>>> I have put the packet captures in
>>>>>>>>
>>>>>>>> http://mseas.mit.edu/download/phaley/GlusterUsers/TestNFSmount/
>>>>>>>>
>>>>>>>> capture_nfsfail.pcap   has the results from the failed touch
>>>>>>>> experiment
>>>>>>>> capture_nfssucceed.pcap  has the results from the successful touch
>>>>>>>> experiment
>>>>>>>>
>>>>>>>> The command I used for these was
>>>>>>>>
>>>>>>>> tcpdump -i ib0 -nnSs 0 host 172.16.1.119 -w
>>>>>>>> /root/capture_nfstest.pcap
>>>>>>
>>>>>> I hope these pkts were captured on the node where NFS server is
>>>>>> running. Could you please use '-i any' as I do not see glusterfs
>>>>>> traffic in the tcpdump.
>>>>>>
>>>>>> Also looks like NFS v4 is used between client & nfs server. Are you
>>>>>> using kernel-NFS here (i.e, kernel-NFS exporting fuse mounted 
>>>>>> gluster
>>>>>> volume)?
>>>>>> If that is the case please capture fuse-mnt logs as well. This error
>>>>>> may well be coming from kernel-NFS itself before the request is sent
>>>>>> to fuse-mnt process.
>>>>>>
>>>>>> FWIW, we have below option -
>>>>>>
>>>>>> Option: server.manage-gids
>>>>>> Default Value: off
>>>>>> Description: Resolve groups on the server-side.
>>>>>>
>>>>>> I haven't looked into what this option exactly does. But it may 
>>>>>> worth
>>>>>> testing with this option on.
>>>>>>
>>>>>> Thanks,
>>>>>> Soumya
>>>>>>
>>>>>>
>>>>>>>>
>>>>>>>> The brick log files are also in the above link.  If I read them
>>>>>>>> correctly they both funny times.  Specifically I see entries from
>>>>>>>> around 2017-06-27 14:02:37.404865  even though the system time was
>>>>>>>> 2017-06-27 12:00:00.
>>>>>>>>
>>>>>>>> One final item, another reply to my post had a link for possible
>>>>>>>> problems that could arise from users belonging to too many 
>>>>>>>> group. We
>>>>>>>> have seen the above problem even with a user belonging to only 4
>>>>>>>> groups.
>>>>>>>>
>>>>>>>> Let me know what additional information I can provide.
>>>>>>
>>>>>>>>
>>>>>>>> Thanks
>>>>>>>>
>>>>>>>> Pat
>>>>>>>>
>>>>>>>>
>>>>>>>> On 06/27/2017 02:45 AM, Soumya Koduri wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On 06/27/2017 10:17 AM, Pranith Kumar Karampuri wrote:
>>>>>>>>>> The only problem with using gluster mounted via NFS is that it
>>>>>>>>>> does not
>>>>>>>>>> respect the group write permissions which we need.
>>>>>>>>>>
>>>>>>>>>> We have an exercise coming up in the a couple of weeks. It seems
>>>>>>>>>> to me
>>>>>>>>>> that in order to improve our write times before then, it 
>>>>>>>>>> would be
>>>>>>>>>> good
>>>>>>>>>> to solve the group write permissions for gluster mounted via
>>>>>>>>>> NFS now.
>>>>>>>>>> We can then revisit gluster mounted via FUSE afterwards.
>>>>>>>>>>
>>>>>>>>>> What information would you need to help us force gluster
>>>>>>>>>> mounted via
>>>>>>>>>> NFS
>>>>>>>>>> to respect the group write permissions?
>>>>>>>>>
>>>>>>>>> Is this owning group or one of the auxiliary groups whose write
>>>>>>>>> permissions are not considered? AFAIK, there are no special
>>>>>>>>> permission checks done by gNFS server when compared to gluster
>>>>>>>>> native
>>>>>>>>> client.
>>>>>>>>>
>>>>>>>>> Could you please provide simple steps to reproduce the issue and
>>>>>>>>> collect pkt trace and nfs/brick logs as well.
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Soumya
>>>>>>>>
>>>>>>>
>>>>>
>>>
>>

-- 

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Pat Haley                          Email:  phaley at mit.edu
Center for Ocean Engineering       Phone:  (617) 253-6824
Dept. of Mechanical Engineering    Fax:    (617) 253-8125
MIT, Room 5-213                    http://web.mit.edu/phaley/www/
77 Massachusetts Avenue
Cambridge, MA  02139-4301

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