[Gluster-users] Data on gluster volume gone

[Raghavendra Gowdappa]

On Thu, Sep 20, 2018 at 1:29 AM, Raghavendra Gowdappa <rgowdapp at redhat.com>
wrote:

> Can you give volume info? Looks like you are using 2 way replica.
>

Yes indeed.
    gluster volume create gvol0 replica 2 gfs01:/glusterdata/brick1/gvol0
gfs02:/glusterdata/brick2/gvol0

+Pranith. +Ravi.

Not sure whether 2 way replication has caused this. From what I understand
we need either 3 way replication or arbiter for correct resolution of heals.


> On Wed, Sep 19, 2018 at 9:39 AM, Johan Karlsson <Johan.Karlsson at dgc.se>
> wrote:
>
>> I have two servers setup with glusterFS in replica mode, a single volume
>> exposed via a mountpoint. The servers are running Ubuntu 16.04 LTS
>>
>> After a package upgrade + reboot of both servers, it was discovered that
>> the data was completely gone. New data written on the volume via the
>> mountpoint is replicated correctly, and gluster status/info commands states
>> that everything is ok (no split brain scenario or any healing needed etc).
>> But the previous data is completely gone, not even present on any of the
>> bricks.
>>
>> The following upgrade was done:
>>
>> glusterfs-server:amd64 (4.1.0-ubuntu1~xenial3 -> 4.1.4-ubuntu1~xenial1)
>> glusterfs-client:amd64 (4.1.0-ubuntu1~xenial3 -> 4.1.4-ubuntu1~xenial1)
>> glusterfs-common:amd64 (4.1.0-ubuntu1~xenial3 -> 4.1.4-ubuntu1~xenial1)
>>
>> The logs only show that connection between the servers was lost, which is
>> expected.
>>
>> I can't even determine if it was the package upgrade or the reboot that
>> caused this issue, but I've tried to recreate the issue without success.
>>
>> Any idea what could have gone wrong, or if I have done some wrong during
>> the setup. For reference, this is how I've done the setup:
>>
>> ---
>> Add a separate disk with a single partition on both servers (/dev/sdb1)
>>
>> Add gfs hostnames for direct communication without DNS, on both servers:
>>
>> /etc/hosts
>>
>> 192.168.4.45    gfs01
>> 192.168.4.46    gfs02
>>
>> On gfs01, create a new LVM Volume Group:
>>   vgcreate gfs01-vg /dev/sdb1
>>
>> And on the gfs02:
>>   vgcreate gfs02-vg /dev/sdb1
>>
>> Create logical volumes named "brick" on the servers:
>>
>> gfs01:
>>   lvcreate -l 100%VG -n brick1 gfs01-vg
>> gfs02:
>>   lvcreate -l 100%VG -n brick2 gfs02-vg
>>
>> Format the volumes with ext4 filesystem:
>>
>> gfs01:
>>   mkfs.ext4 /dev/gfs01-vg/brick1
>> gfs02:
>>   mkfs.ext4 /dev/gfs02-vg/brick2
>>
>> Create a mountpoint for the bricks on the servers:
>>
>> gfs01:
>>   mkdir -p /glusterdata/brick1
>> gds02:
>>   mkdir -p /glusterdata/brick2
>>
>> Make a permanent mount on the servers:
>>
>> gfs01:
>> /dev/gfs01-vg/brick1    /glusterdata/brick1     ext4    defaults
>> 0     0
>> gfs02:
>> /dev/gfs02-vg/brick2    /glusterdata/brick2     ext4    defaults
>> 0     0
>>
>> Mount it:
>>   mount -a
>>
>> Create a gluster volume mount point on the bricks on the servers:
>>
>> gfs01:
>>   mkdir -p /glusterdata/brick1/gvol0
>> gfs02:
>>   mkdir -p /glusterdata/brick2/gvol0
>>
>> From each server, peer probe the other one:
>>
>>   gluster peer probe gfs01
>> peer probe: success
>>
>>   gluster peer probe gfs02
>> peer probe: success
>>
>> From any single server, create the gluster volume as a "replica" with two
>> nodes; gfs01 and gfs02:
>>
>>   gluster volume create gvol0 replica 2 gfs01:/glusterdata/brick1/gvol0
>> gfs02:/glusterdata/brick2/gvol0
>>
>> Start the volume:
>>
>>   gluster volume start gvol0
>>
>> On each server, mount the gluster filesystem on the /filestore mount
>> point:
>>
>> gfs01:
>>   mount -t glusterfs gfs01:/gvol0 /filestore
>> gfs02:
>>   mount -t glusterfs gfs02:/gvol0 /filestore
>>
>> Make the mount permanent on the servers:
>>
>> /etc/fstab
>>
>> gfs01:
>>   gfs01:/gvol0 /filestore glusterfs defaults,_netdev 0 0
>> gfs02:
>>   gfs02:/gvol0 /filestore glusterfs defaults,_netdev 0 0
>> ---
>>
>> Regards,
>>
>> Johan Karlsson
>> _______________________________________________
>> Gluster-users mailing list
>> Gluster-users at gluster.org
>> https://lists.gluster.org/mailman/listinfo/gluster-users
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.gluster.org/pipermail/gluster-users/attachments/20180920/62e3aff7/attachment.html>