noob questions about proxmox cluster

[abubin]

I just discovered proxmox and find it to be fanstastic!! I have been using other virtualization software like vmware, virtualbox and so on. However, what attracted me to proxmox is the clustering feature out of the box. Really neat feature and important one too considering everyone talking about cloud computing nowadays.

Anyway, I have some really noob questions about clustering in proxmox which I can't find the answer to.

1) I read in docs about getting the hardware for clustering to be as equal as possible. Why is that? Doesn't the virtual environment create the same type of 'hardware' in the eyes of the VMs? We can't possible do that when let's say we add a new server into the cluster 2 years later.
2) what about the proxmox version? Must they all be the same? Again, let's say we add another server 2 years later when there are already new version out. This leads to question 3.
3) how easy it is to upgrade proxmox especially when they are running in clusters?
4) do we need to pay for using cluster?
5) is it hard to setup vm failover in cluster? Or even possible?

 

[mir]

1) I read in docs about getting the hardware for clustering to be as equal as possible. Why is that? Doesn't the virtual environment create the same type of 'hardware' in the eyes of the VMs? We can't possible do that when let's say we add a new server into the cluster 2 years later.

This just referrer to CPU and chipset. Either choose AMD or Intel for all. Generally it seems Intel has better support. Myself using AMD so this is based on hear/say since I have no problems with my AMD setup.

2) what about the proxmox version? Must they all be the same? Again, let's say we add another server 2 years later when there are already new version out. This leads to question 3.

Yes. The only situation where this is not true is the time where you are upgrading.

3) how easy it is to upgrade proxmox especially when they are running in clusters?

This can be done from the gui or using apt-get update && apt-get dist-upgrade from the command line. Only thing needed is to migrate all running VM's to other node before doing the upgrade.

4) do we need to pay for using cluster?

No.

5) is it hard to setup vm failover in cluster? Or even possible?

Failover is possible but most be done from command line. Search the forum for examples.

 

[abubin]

This can be done from the gui or using apt-get update && apt-get dist-upgrade from the command line. Only thing needed is to migrate all running VM's to other node before doing the upgrade.

Hmm..this would means I need to have enough free resources to cater for the VMs in another server for the upgrade. What if I do not have enough free resources or if I only have 1 server, how do I go about upgrading?

 

[mir]

Hmm..this would means I need to have enough free resources to cater for the VMs in another server for the upgrade. What if I do not have enough free resources or if I only have 1 server, how do I go about upgrading?

If you only have 1 server then HA is not an option. In case of lack of resources your only option is to stop the VM's.

 

[abubin]

Does the clustering of proxmox only for HA? Means when I create 1 VM, it will be replicated to all the cluster. Compared to running various VMs and only apply HA to certain VMs that need it. Also, is it possible to apply HA on VMs as when it is needed. Like need to take the 1 server down to upgrades/maintenance. Move the VMs to server 2. Then once upgrade done, move back the VMs to server 1 and then destroy the copy in server 2

 

[m.ardito]

Like need to take the 1 server down to upgrades/maintenance. Move the VMs to server 2. Then once upgrade done, move back the VMs to server 1 and then destroy the copy in server 2

If you need to to that manually, you can do that without HA: you just need shared storage, like a NFS/ISCI nas box.
move VM disks on the shared storage (no downtime), so when you need migrate the VMs to another node, it's really fast.

Marco

 

[abubin]

once the VM is copied to the new box, obviously when need to switchover the new VM means need to be brought down?

note: nevermind..i think I found the answer to this.
It will depends on whether the storage is in same machine or in a storage machine. If the VM is located in storage machine then I can switch over without downtime.

I am starting to like proxmox even more. Very promising and easy to use unlike those really complicated openstack,eucalyptus,opencloud and so on.

 

[m.ardito]

If the VM is located in storage machine then I can switch over without downtime.

with recent proxmox ve you have
* live vm migration (move machine between clustee nodes without downtime) see http://pve.proxmox.com/wiki/Backup_-_Restore_-_Live_Migration
* live storage migration (convert single vm disks between defined storages and types without downtime) see http://pve.proxmox.com/wiki/Storage_Migration

both are designed and should work online (ie live, no downtime) but will work offline too.

Marco

 

[abubin]

this is cool!! I am going to give this a try. If all works out, I can get my company to purchase license. Love a community that is active and supportive!