4:32 a.m.
I am facing this trouble since version 4.1 up to the latest 4.2.4, once
we enable gluster snapshots and accumulate some snapshots (as few as 15
snapshots per server) we start having trouble booting the server. The
server enters emergency shell upon boot after timing out waiting for
snapshot devices. Waiting a few minutes and pressing Control-D then boots the server
normally. In case of very large number of snapshots (600+) it can take days before the
sever will boot. Attaching journal
log, let me know if you need any other logs.
Details of the setup:
3 node hyperconverged oVirt setup (64GB RAM, 8-Core E5 Xeon)
oVirt 4.2.4
oVirt Node 4.2.4
10Gb Interface
Thanks,
Hesham S. Ahmed
4:59 a.m.
I also noticed that Gluster Snapshots have the SAME UUID as the main
LV and if using UUID in fstab, the snapshot device is sometimes
mounted instead of the primary LV
For instance:
/etc/fstab contains the following line:
UUID=a0b85d33-7150-448a-9a70-6391750b90ad /gluster_bricks/gv01_data01
auto inode64,noatime,nodiratime,x-parent=dMeNGb-34lY-wFVL-WF42-hlpE-TteI-lMhvvt
0 0
# lvdisplay gluster00/lv01_data01
--- Logical volume ---
LV Path /dev/gluster00/lv01_data01
LV Name lv01_data01
VG Name gluster00
# mount
/dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0 on
/gluster_bricks/gv01_data01 type xfs
(rw,noatime,nodiratime,seclabel,attr2,inode64,sunit=1024,swidth=2048,noquota)
Notice above the device mounted at the brick mountpoint is not
/dev/gluster00/lv01_data01 and instead is one of the snapshot devices
of that LV
# blkid
/dev/mapper/gluster00-lv01_shaker_com_sa:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-4ca8eef409ec4932828279efb91339de_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-59992b6c14644f13b5531a054d2aa75c_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-362b50c994b04284b1664b2e2eb49d09_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-0b3cc414f4cb4cddb6e81f162cdb7efe_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-da98ce5efda549039cf45a18e4eacbaf_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
/dev/mapper/gluster00-4ea5cce4be704dd7b29986ae6698a666_0:
UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
Notice the UUID of LV and its snapshots is the same causing systemd to
mount one of the snapshot devices instead of LV which results in the
following gluster error:
gluster> volume start gv01_data01 force
volume start: gv01_data01: failed: Volume id mismatch for brick
vhost03:/gluster_bricks/gv01_data01/gv. Expected volume id
be6bc69b-c6ed-4329-b300-3b9044f375e1, volume id
55e97e74-12bf-48db-99bb-389bb708edb8 found
On Sun, Jul 8, 2018 at 12:32 PM <hsahmed(a)gmail.com> wrote:
>
> I am facing this trouble since version 4.1 up to the latest 4.2.4, once
> we enable gluster snapshots and accumulate some snapshots (as few as 15
> snapshots per server) we start having trouble booting the server. The
> server enters emergency shell upon boot after timing out waiting for
> snapshot devices. Waiting a few minutes and pressing Control-D then boots the server
normally. In case of very large number of snapshots (600+) it can take days before the
sever will boot. Attaching journal
> log, let me know if you need any other logs.
>
> Details of the setup:
>
> 3 node hyperconverged oVirt setup (64GB RAM, 8-Core E5 Xeon)
> oVirt 4.2.4
> oVirt Node 4.2.4
> 10Gb Interface
>
> Thanks,
>
> Hesham S. Ahmed
5:42 a.m.
Apparently this is known default behavior of LVM snapshots and in that
case maybe Cockpit in oVirt node should create mountpoints using
/dev/mapper path instead of UUID by default. The timeout issue
persists even after switching to /dev/mapper/devices in fstab
On Sun, Jul 8, 2018 at 12:59 PM Hesham Ahmed <hsahmed(a)gmail.com> wrote:
>
> I also noticed that Gluster Snapshots have the SAME UUID as the main
> LV and if using UUID in fstab, the snapshot device is sometimes
> mounted instead of the primary LV
>
> For instance:
> /etc/fstab contains the following line:
>
> UUID=a0b85d33-7150-448a-9a70-6391750b90ad /gluster_bricks/gv01_data01
> auto inode64,noatime,nodiratime,x-parent=dMeNGb-34lY-wFVL-WF42-hlpE-TteI-lMhvvt
> 0 0
>
> # lvdisplay gluster00/lv01_data01
> --- Logical volume ---
> LV Path /dev/gluster00/lv01_data01
> LV Name lv01_data01
> VG Name gluster00
>
> # mount
> /dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0 on
> /gluster_bricks/gv01_data01 type xfs
> (rw,noatime,nodiratime,seclabel,attr2,inode64,sunit=1024,swidth=2048,noquota)
>
> Notice above the device mounted at the brick mountpoint is not
> /dev/gluster00/lv01_data01 and instead is one of the snapshot devices
> of that LV
>
> # blkid
> /dev/mapper/gluster00-lv01_shaker_com_sa:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-4ca8eef409ec4932828279efb91339de_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-59992b6c14644f13b5531a054d2aa75c_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-362b50c994b04284b1664b2e2eb49d09_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-0b3cc414f4cb4cddb6e81f162cdb7efe_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-da98ce5efda549039cf45a18e4eacbaf_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
> /dev/mapper/gluster00-4ea5cce4be704dd7b29986ae6698a666_0:
> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>
> Notice the UUID of LV and its snapshots is the same causing systemd to
> mount one of the snapshot devices instead of LV which results in the
> following gluster error:
>
> gluster> volume start gv01_data01 force
> volume start: gv01_data01: failed: Volume id mismatch for brick
> vhost03:/gluster_bricks/gv01_data01/gv. Expected volume id
> be6bc69b-c6ed-4329-b300-3b9044f375e1, volume id
> 55e97e74-12bf-48db-99bb-389bb708edb8 found
>
> On Sun, Jul 8, 2018 at 12:32 PM <hsahmed(a)gmail.com> wrote:
> >
> > I am facing this trouble since version 4.1 up to the latest 4.2.4, once
> > we enable gluster snapshots and accumulate some snapshots (as few as 15
> > snapshots per server) we start having trouble booting the server. The
> > server enters emergency shell upon boot after timing out waiting for
> > snapshot devices. Waiting a few minutes and pressing Control-D then boots the
server normally. In case of very large number of snapshots (600+) it can take days before
the sever will boot. Attaching journal
> > log, let me know if you need any other logs.
> >
> > Details of the setup:
> >
> > 3 node hyperconverged oVirt setup (64GB RAM, 8-Core E5 Xeon)
> > oVirt 4.2.4
> > oVirt Node 4.2.4
> > 10Gb Interface
> >
> > Thanks,
> >
> > Hesham S. Ahmed
6:58 a.m.
On Sun, Jul 8, 2018 at 3:29 PM, Hesham Ahmed <hsahmed(a)gmail.com> wrote:
We do not recommend gluster volume snapshots for volumes hosting VM images.
Please look at the
https://ovirt.org/develop/release-management/features/gluster/gluster-dr/
as an alternative.
7:11 a.m.
Thanks Sahina for the update,
I am using gluster geo-replication for DR in a different installation,
however I was not aware that Gluster snapshots are not recommended in
a hyperconverged setup, don't. A warning on the Gluster snapshot UI
would be helpful. Is gluster volume snapshots for volumes hosting VM
images a work in progress with a bug tracker or it's something not
expected to change?
On Mon, Jul 9, 2018 at 2:58 PM Sahina Bose <sabose(a)redhat.com> wrote:
>
>
>
> On Sun, Jul 8, 2018 at 3:29 PM, Hesham Ahmed <hsahmed(a)gmail.com> wrote:
>>
>> I also noticed that Gluster Snapshots have the SAME UUID as the main
>> LV and if using UUID in fstab, the snapshot device is sometimes
>> mounted instead of the primary LV
>>
>> For instance:
>> /etc/fstab contains the following line:
>>
>> UUID=a0b85d33-7150-448a-9a70-6391750b90ad /gluster_bricks/gv01_data01
>> auto inode64,noatime,nodiratime,x-parent=dMeNGb-34lY-wFVL-WF42-hlpE-TteI-lMhvvt
>> 0 0
>>
>> # lvdisplay gluster00/lv01_data01
>> --- Logical volume ---
>> LV Path /dev/gluster00/lv01_data01
>> LV Name lv01_data01
>> VG Name gluster00
>>
>> # mount
>> /dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0 on
>> /gluster_bricks/gv01_data01 type xfs
>> (rw,noatime,nodiratime,seclabel,attr2,inode64,sunit=1024,swidth=2048,noquota)
>>
>> Notice above the device mounted at the brick mountpoint is not
>> /dev/gluster00/lv01_data01 and instead is one of the snapshot devices
>> of that LV
>>
>> # blkid
>> /dev/mapper/gluster00-lv01_shaker_com_sa:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-55e97e7412bf48db99bb389bb708edb8_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-4ca8eef409ec4932828279efb91339de_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-59992b6c14644f13b5531a054d2aa75c_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-362b50c994b04284b1664b2e2eb49d09_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-0b3cc414f4cb4cddb6e81f162cdb7efe_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-da98ce5efda549039cf45a18e4eacbaf_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>> /dev/mapper/gluster00-4ea5cce4be704dd7b29986ae6698a666_0:
>> UUID="a0b85d33-7150-448a-9a70-6391750b90ad" TYPE="xfs"
>>
>> Notice the UUID of LV and its snapshots is the same causing systemd to
>> mount one of the snapshot devices instead of LV which results in the
>> following gluster error:
>>
>> gluster> volume start gv01_data01 force
>> volume start: gv01_data01: failed: Volume id mismatch for brick
>> vhost03:/gluster_bricks/gv01_data01/gv. Expected volume id
>> be6bc69b-c6ed-4329-b300-3b9044f375e1, volume id
>> 55e97e74-12bf-48db-99bb-389bb708edb8 found
>
>
>
> We do not recommend gluster volume snapshots for volumes hosting VM images. Please
look at the https://ovirt.org/develop/release-management/features/gluster/gluster-dr/ as
an alternative.
>
>>
>> On Sun, Jul 8, 2018 at 12:32 PM <hsahmed(a)gmail.com> wrote:
>> >
>> > I am facing this trouble since version 4.1 up to the latest 4.2.4, once
>> > we enable gluster snapshots and accumulate some snapshots (as few as 15
>> > snapshots per server) we start having trouble booting the server. The
>> > server enters emergency shell upon boot after timing out waiting for
>> > snapshot devices. Waiting a few minutes and pressing Control-D then boots
the server normally. In case of very large number of snapshots (600+) it can take days
before the sever will boot. Attaching journal
>> > log, let me know if you need any other logs.
>> >
>> > Details of the setup:
>> >
>> > 3 node hyperconverged oVirt setup (64GB RAM, 8-Core E5 Xeon)
>> > oVirt 4.2.4
>> > oVirt Node 4.2.4
>> > 10Gb Interface
>> >
>> > Thanks,
>> >
>> > Hesham S. Ahmed
>
>
7:52 a.m.
On Mon, Jul 9, 2018 at 5:41 PM, Hesham Ahmed <hsahmed(a)gmail.com> wrote:
Agreed on the warning - can you log a bz?
There's no specific bz tracking support for volume snapshots w.r.t VM store
use case. If you have a specific scenario where the geo-rep based DR is not
sufficient, please log a bug.
On Mon, Jul 9, 2018 at 2:58 PM Sahina Bose <sabose(a)redhat.com> wrote:
10:53 a.m.
On Mon, Jul 9, 2018 at 3:52 PM Sahina Bose <sabose(a)redhat.com> wrote:
Bug report created for the warining
https://bugzilla.redhat.com/show_bug.cgi?id=1599365
We were not using gluster snapshots for DR rather as a quick way to go
back in time (although we never planned how to use the snapshots).
Maybe scheduling ability should be added for VM snapshots as well.
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7 comments
4 participants
participants (4)
-
Hesham Ahmed -
hsahmed＠gmail.com
-
Maor Lipchuk -
Sahina Bose