RE: [Xen-users] RE: Tutorial : Debian, Xen and CLUSTER / GFS Supp ort

[PAINCHAUD Christophe <cpainchaud@xxxxxxxxxxx>]

>> >In theory.  In practice, the snapshot target is horribly unstable and
>> >will nuke your data sooner rather than later :-).
>> is
>> much more stable.
>
>It's being actively developed?  Sounds good!
Actively is not the word I think... bug fixes so far.

>I thought it was a dead thing, haven't seen a single thread about it
>on dm-devel for at least 6 months.
>
>Which ML did you see activity on ?
I can see quite a few threads on https://www.redhat.com/archives/dm-devel/
But, unless I am wrong DM and LVM are included in the kernel tree, so kernel maintainers are working on these bugfixes too I think.

>> I'am trying to use snapshot features under heavy IO stress
>> and so far no problem. I will test and dig a bit more in the ML to be >>sure
>> that is working as intended.

>How are you testing?
>Which patches to dm-snapshot are you using?
>I've got an HP ProLiant (x86_64) here that's not going into production
>for a month.  I'd like to chip in with some dm-snapshot (vs. Xen)
>testing.
For my LVM/DM snapshot tests, I have created 4 block devices of 8GB in LVM group of 50GB. I am using DM and LVM2 libs and daemon from the Debian Etch packages. I wrote a program to write randomly in the 4 block devices (it looks like it's write about 20MB/s, I didn't really optimize it.). While this program is active, I do a snapshot of the first volume, and copy it on a tape device, I destroy snapshot, then do the same with second, third and fourth volume. I launched the loop of snapshot/backups many times in day without a single problem.

My test were made on a Dell 1750 (32bit) with a Perc 3D/I SCSI card.

Did you experience any problem?

Regards,

        Christophe Painchaud

Christophe Painchaud

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users