For those using iSCSI shared storage - Ways to prevent single VM from using all IOPS?

[Giovanni]

Hi guys

I am myself testing iSCSI target and initiators with FreeNAS and I have not yet installed proxmox (need to go pickup another server at the datacenter when I get a chance).

I have been wondering since I guess proxmox will use an iSCSI connector to make the connection to the storage target - I am imaging that there is no limit on IOPS that can be requested on a per VM basis. That means say I install 2 VM's in proxmox one windows and another linux.

If I were to benchmark/burn-in tests the storage by sending IO requests for write and read (not throughput) it could theorically crash/slow down the NAS storage server, am I correct on this assumption?

If yes it could happen anything that can be done to avoid it - or is there a way to prevent it, either by manually setting it right now via workarounds or in future versions? is there a virtualization platform (either commercial or open source) that actually has this capability yet or is this all in my head? I want to avoid placing 10 VM's on a single proxmox node connected to an iscsi node and then suddenly 1 single VM uses all available resources IOPS.

Thanks

 

[whinpo]

Re: For those using iSCSI shared storage - Ways to prevent single VM from using all I

if you use a shared storage, you will have only one LUN for all your VM.
If you run a cluster, this LUN will be shared between your Proxmox VE servers.

That's the Proxmox VE server that will be using iSCSI (via open-iscsi) to access the data, the VM won't even know there is an iSCSI connection somewhere...

Applying an IO limitation to a specific VM would imply allow a limitation to a part of a disk (an LV of the LVM)....

I don't know if it could really be possible, but i doubt...