Remove one host from cluster...

[andrea68]

Hi,

I have 1 little cluster, proxmox 2.1 based on 2 host (no HA).
I need to clean upgrade one host (the other one follow later).

So I move all VM on host1 and now I'm prepared to remove Host2 from the cluster and reset the server.

My goal is to install Proxmox 3.1 and move all the VM's on this new host (from a backup on a NAS) so I can format also the primary server (Host1)...

I'm reading now this guide: https://pve.proxmox.com/wiki/Proxmox_VE_2.0_Cluster
and it seems very scary regarding removing host from a cluster, there's some other advice that must I follow in this procedure?
It is safe to remove one host from the cluster and then reset?

Thanks in advance.

 

[m.ardito]

Hi, it should go fine. If you name the new host as the old one, it may be necessary to add it with -force option, but try without first.
If you name the new host with a new name, never "seen" before by the cluster, it should add smoothly.

If you wish to really try first, you can experiment creating a "nested" pve cluster (I documented how here http://pve.proxmox.com/wiki/Nested_Virtualization), just to experiment in building, changing and even destroying a test cluster.

Marco

 

[andrea68]

Thank you very much Marco, I'll try for sure, I was concerned about the warning in wiki page...

I try also nested cluster pve (on a VMWare fusion!) some years ago and it worked, but not this specific operation.

Thanks again...

 

[udo]

Hi,
why you wan't to remove the host from the cluster? You have the old cluster for ugrade only, or?
You need quorum in the old cluster (expected votes) and than create an new cluster on the new pve-3 host.

But you wrote clean update? For me it's looks more than a fresh installation?!

If you have shared storage, you can "migrate" the VMs (mean copy config) from old cluster to the new host without longer downtime (as like backup/restore).

Udo

 

[andrea68]

Hi,
why you wan't to remove the host from the cluster? You have the old cluster for ugrade only, or?
You need quorum in the old cluster (expected votes) and than create an new cluster on the new pve-3 host.

But you wrote clean update? For me it's looks more than a fresh installation?!

If you have shared storage, you can "migrate" the VMs (mean copy config) from old cluster to the new host without longer downtime (as like backup/restore).

Udo

Hi Udo,

for the moment I have just 2 host in cluster, no HA use, just for simpler administration.
I figured out it's better a clean update (yes I meaning a fresh installation) because is a very old installation with some modifications ...

So i was thinking to reformat ad install one host at a time and use a NFS storage backup to migrate the VM's...

 

[udo]

Hi Udo,

for the moment I have just 2 host in cluster, no HA use, just for simpler administration.
I figured out it's better a clean update (yes I meaning a fresh installation) because is a very old installation with some modifications ...

So i was thinking to reformat ad install one host at a time and use a NFS storage backup to migrate the VM's...

Hi Andrea,
only local storage, or something like DRBD? Also with DRBD you can sync between 2.x and 3.x to migrate the VMs.

With local-storage only is the backup/restore way the best choice.

Udo

 

[andrea68]

Yes, just local storage, so I will do a backup/restore as you said...

Now I have a problem also with backup, I opened another thread about it.
But I think it's a NAS problem...