HA Cluster with 2 Nodes, Backup

[guyman]

Hi,

First: Have a happy new year for everyone .

Second: I plan to setup a HA-Cluster using this guide: http://pve.proxmox.com/wiki/Two-Node_High_Availability_Cluster

Will it work without the Quorum Disk (3rd node at all in general)? I want to use DRBD with LVM on it.

Also: In the past I had some problems with LVM-nodes when the secondary DRBD becames master in a fail-over-scenario. I had to create a small init-script to re-use LVM again. Will it work without no problems?

Third: In the past I could not use whole size of the disk for one LVM because it needed some space left to create snapshot-partitions when performing backups (snapshot-mode). Is this still nessescarry? If yes, how big should it be? Is the size based of the max-amount of disk-space a VE has or are 20 / 30 G ok for the data which newly appear when performing backups?

And at last: I found out with Proxmox 1 / 2 it was not directly possible to use openVZ with DRBD/LVM. (see http://pve.proxmox.com/wiki/DRBD). Is it directly possible with Proxmox 3.1?

Thank you!

 

[thheo]

You can check my topic: http://forum.proxmox.com/threads/17382-HA-migration-on-node-failure-restarts-VMs
I just finished the setup of such a scenario, except that I didn't want to use lvm and just put GFS2 on top of drbd.
Right now I am doing I/O performance tests just to make sure I won't hit any bottlenecks..
CLVM should work ok so you don't need scripts..

 

[guyman]

Thanks. So there is need for quorum disk at all ;-( ?

 

[thheo]

There is a need for quorum. You can have it with a 3rd proxmox node which can be any machine ( you'll not run VMs on it.. just for quorum )
or you can have it via a quorum disk. Basically you need a 3rd party to tell you which node is going "nuts"..
Also quorum disk can be very easily implemented ( as described on wiki ). It is recommended to have it close enough so that you can have minimum latency.