S.M.A.R.T. in KVM on virtio drive

namron

New Member
Aug 27, 2015
19
0
1
Hi,

I use passtrough to make hdds, that are physically connected to my hypervisor available to a VM.

For example with code like this:

Code:
qm set 102 -virtio1 /dev/disk/by-id/ata-TOSHIBA_DT01ACA300_548XGR9GS
Accessing the hdd from within the VM works fine, except SMART and device info. It seems like no drive infos like vendor, serial, etc. and SMART data are passed through.

Did I miss some additional arguments in my command or is it just not possible to have it work this way?
 

namron

New Member
Aug 27, 2015
19
0
1
No, I haven't because I thought virtio to be superior over the other alternatives
 

namron

New Member
Aug 27, 2015
19
0
1
I am mainly concerned with speed. Does the additional scsi layer impact performance?

If I give it a try which SCSI Controller Type should I use?
 

namron

New Member
Aug 27, 2015
19
0
1
Allright. Changed the passthrough to SCSI and SMART works now. Thank you.

Another topic:
My host runs on an AMD A10-5700 APU. 1 socket, 4 cores.
What is an intelligent way to assign coren to 3 VMs, which experience nearly the same load?
Each VM with 1 socket, 2 cores?
 

LnxBil

Famous Member
Feb 21, 2015
4,439
443
103
Germany
The overhead of multiple cores is not only on the cpu, it's also on memory. In multicore systems you often need to spawn processes for each core, so your "minimal" host with only a few "real" (user land) processes have almost doubled number of processes due to a core increase from 1 to 2 cores. This yields for more used memory - it's not that much, but it is more and you also need more CPU cycles to maintain these operations and stuff. Yet in the end, I don't think that you'll have to worry about that. As long as you have a load level in your host that is lower than the number of cores you're fine. You should not assign more cores to your VM than you physically have, but I think that's clear.

In my experience, you're almost never bound by cpu power in a virtualized system, it's always I/O or memory. If you really need that much CPU power, you would not use the low-end apu for that, but a beasty dual or quad socket 24 core Xeon :-D
 

namron

New Member
Aug 27, 2015
19
0
1
Does this really work? I am using Proxmox VE 4.4 and because of issues with PCI Passthrough (https://forum.proxmox.com/threads/promxox4-4-qm-status-stopped-for-passthrough-of-ibm1015.32841/#post-168599) of my SAS2008 Controller I tried using drive passthrough. I tried using sata0: and scsi0: with virtio-scsi-pci but in both cases I am unable to access SMART values inside the guest. How can one pull this off?
It doesn't work.

I do SMART directly in proxmox now.
 

About

The Proxmox community has been around for many years and offers help and support for Proxmox VE and Proxmox Mail Gateway. We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!