High Availability Questions

[candre]

Hi there,

First of all Proxmox is a great product loving it so far, simple and easy to use but still pretty feature rich.

A couple of questions regarding HA.

1.) How does Proxmox decide which host to migrate the Machine to?
2.) What would happen if proxmox was restarting on another node and the server that it was restarting on also died while it was restarting (would it then fail over to another node).
3.) Not really HA question but is there anything planned for proxmox to do a dynamic distribution based on load. I.e say one server had 10 VPSs on it while another one had 2-3 VPSs not really doing anything, proxmox would then balance out the load across those 2 servers by automatically live migrating across.

Thanks

Chris

 

[tom]

Hi there,

First of all Proxmox is a great product loving it so far, simple and easy to use but still pretty feature rich.

A couple of questions regarding HA.

1.) How does Proxmox decide which host to migrate the Machine to?

the resource manager decide this (rgmanager), based on the defined cluster.conf.

2.) What would happen if proxmox was restarting on another node and the server that it was restarting on also died while it was restarting (would it then fail over to another node).

you need always quorum. if you loose quorum, rgmanager cannot start any VM.

3.) Not really HA question but is there anything planned for proxmox to do a dynamic distribution based on load. I.e say one server had 10 VPSs on it while another one had 2-3 VPSs not really doing anything, proxmox would then balance out the load across those 2 servers by automatically live migrating across.

Thanks

Chris

doing this automatically is problematic by design. if you have high load and you start live migration you get even higher load. I am not aware of any admin running such setups with great success.

 

[candre]

Hi Tom ,

Thanks for the fast reply. Thats great, I momentarily forgot that it uses corosync so thats great. Just had a question as we are planning on using Ceph RBD. How would backups perform on Ceph. Is it possible to do a Live backup (i.e no downtime) while utilising ceph as a storage server?

Thanks

Kind Regards

Chris

 

[candre]

Thanks for the fast reply Tom,

We are looking at using a CEPH Rados storage for the shared storage. Just wondering if snapshots and backups work with the RBD plugin? And do online backups work as well using CEPH?

Thanks

Kind Regards

Chris

 

[dietmar]

Is it possible to do a Live backup (i.e no downtime) while utilising ceph as a storage server?

We plan to support that in the next release.

 

[tom]

that's the idea, yes.