Ceph or DRBD or else for for 3 node cluster ?

[tytanick]

Hi
I have 3 nodes based on proxmox 4.2
On every node i have whole /dev/sdb free to use as shared ssd storage.


Now.. Tell me this?
I would like this shared storage to be stable because it will be in production
I want HA on cluster so i need shared storage - please suggest what is the best move for me:

a) drbd replication primary-primary on two nodes and leave third without drbd but only for cluster quorum ?
b) drbd on three nodes primary-primary-primary (might be unstable ?)
c) can i use ceph because moderator told me that i need more disks to make it wok ? is ist true ? Cant i use ceph on 4 nodes (on /dev/sdb ?)
d) can i use anything else as software shared storage?

 

[tytanick]

anyone ?

 

[tom]

DRBD9 could be a way, but this is not yet stable. (still technology preview).

Ceph with just 1 OSD will be slow.

Maybe gluster is an option here.

 

[tytanick]

thx for answer

I dont really understand why ceph is slow if there are one disk on each node (and this disk is ssd). Drbd has no problems with that as i tested.
Can i make
/dev/sdb1
/dev/sdb2
/dev/sdb3
as "more OSD" ?

And what about drbd 8 ? - is this more stable than 9 ?

About gluster i have problems on other setup - live migration causes split brain so i dont like it.

 

[Firm]

If you want to use partitions as OSD disks then you have to create/initialize them manually, not with pveceph createosd command (you will need to set correct partition type GUID and name them as 'ceph data').

 

[tom]

thx for answer

I dont really understand why ceph is slow if there are one disk on each node (and this disk is ssd).

Read more on http://ceph.com/ - Ceph is not fast on small number of hosts and just a few OSDs. But yes, SSD is faster than spinning disks.

Drbd has no problems with that as i tested.
Can i make
/dev/sdb1
/dev/sdb2
/dev/sdb3
as "more OSD" ?

no.

And what about drbd 8 ? - is this more stable than 9 ?

DRBD8 is not available for Proxmox VE 4.x. So if you want DRBD, you need to use V9.

About gluster i have problems on other setup - live migration causes split brain so i dont like it.

I personally do not have much experience with gluster, if I need shared storage I always go for Ceph.