2017-10-11 15:37 GMT+02:00 ML <lists@xxxxxxxxxxxxxxx>:
After some extra reading about LVM snapshots & Gluster, I think I can conclude it may be a bad idea to use it on big storage bricks.
I understood that the LVM maximum metadata, used to store the snapshots data, is about 16GB.
LVM metadata aer used to store changed METADATA, not data. thin-provisioned snapshots usually may grow up to the local unallocated capacity.
So if I have a brick with a volume arount 10TB (for example), daily snapshots, files changing ~100GB : the LVM snapshot is useless.
LVM's snapshots doesn't seems to be a good idea with very big LVM partitions.
Did I missed something ? Hard to find clear documentation on the subject.
LVM documentation (RH has very good docs available via web) and even the lvcreate man page is OK. not a lightweight read but OK. You need thin-provisioned lvm pools to have snapshots in gluster.
Le 11/10/2017 à 09:07, Ric Wheeler a écrit :
On 10/11/2017 09:50 AM, ML wrote:
Hi everyone,
I've read on the gluster & redhat documentation, that it seems recommended to use XFS over LVM before creating & using gluster volumes.
Sources :
https://access.redhat.com/documentation/en-US/Red_Hat_Storag e/3/html/Administration_Guide/ Formatting_and_Mounting_Bricks .html
http://gluster.readthedocs.io/en/latest/Administrator%20Guid e/Setting%20Up%20Volumes/
My point is : do we really need LVM ?
For example , on a dedicated server with disks & partitions that will not change of size, it doesn't seems necessary to use LVM.
I can't understand clearly wich partitioning strategy would be the best for "static size" hard drives :
1 LVM+XFS partition = multiple gluster volumes
or 1 LVM+XFS partition = 1 gluster volume per LVM+XFS partition
or 1 XFS partition = multiple gluster volumes
or 1 XFS partition = 1 gluster volume per XFS partition
What do you use on your servers ?
Thanks for your help! :)
Quentin
Hi Quentin,
Gluster relies on LVM for snapshots - you won't get those unless you deploy on LVM.
Regards,
Ric
_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users
_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users
_______________________________________________ Gluster-users mailing list Gluster-users@xxxxxxxxxxx http://lists.gluster.org/mailman/listinfo/gluster-users
