Windows 7 KVM guests

[NetRock]

Hi ....

Below link suggests the best practice to setup Windows 7 OS;
https://pve.proxmox.com/wiki/Windows_7_guest_best_practices

is that the right configuration to setup Windows 7 VM in the Proxmox environment.
Has anyone done any benchmarking of the performance difference between cache=none, cache=writethrough.... CPU-"CPU-Units"-Power or setting other options?
Trying to find the way to get the best performance Windows 7 KVM guests...
Thank YOU in advance for your comments.

 

[nanonettr]

My personel experiences are (mostly on Linux and Windows Servers);
- Linux and Windows : Backing storage is critical for VM performances, use fast disks with RAID10 if possible
- Linux and Windows : Qcow2 is enough for most workloads (use preallocation=metadata) but never use it with ide, always virtio
- Linux and Windows : Did not try anything but nocache for disks, its fast and stable for me (on crash, did not lose any data \o/... yet... )
- Windows : e1000 does not show network graphs in task manager need to load intel driver or use virtio
- Windows : seems faster and more stable without balloon, avoid it if possible

 

[NetRock]

Thanks for the reply....

* For Storage: I should forget "IDE", "SATA" and "SCSI" ..... use ONLY "VIRTIO", that is what you suggesting?
* For NIC; e1000 has a better performance or virtio. Do you know which one is a better choice for Windows OS.

Thanks.

 

[nanonettr]

Thanks for the reply....

* For Storage: I should forget "IDE", "SATA" and "SCSI" ..... use ONLY "VIRTIO", that is what you suggesting?
* For NIC; e1000 has a better performance or virtio. Do you know which one is a better choice for Windows OS.

Thanks.

IDE is painfully slow.
SATA has migration problems. Cant live migrate a VM to another Proxmox node. I did not do any benchmark for this reason.
SCSI with controller type VIRTIO is fast also supports discard (TRIM). Actually i am using this for my VMs.
VIRTIO is also fast.

You can use VIRTIO or SCSI with VIRTIO controller. Both are stable and fast.

About network performance;
I am using Proxmox since version 1.5. In that days Virtio had some issues so i used to use e1000.

But now everything is mature. I am using Virtio with multiqueues, did not make bencmarks but read some documents about it, i think this is the way to go.
Virtio is 10G, that means faster connections between VMs on the same node

Also my main concern is stability. So i am not choosing the emulated hardware based on performance.
If my virtualization setup has %85 bare metal performance without any problems its OK for me.

 

[NetRock]

Hi ... Thank you for your great help.....
Proxmox is installed on a hardware without any RAIDS.
How would you setup the windows OS VM with SCSI storage and Virtio controller...
could you please explain ...
Thanks

 

[nanonettr]

How would you setup the windows OS VM with SCSI storage and Virtio controller...

You have three way for this, third one is my preferred way.

1) Install with IDE then shutdown.
Add a secondary virtio drive. Place virtio iso to cd drive.
Start VM after boot install drivers. Shutdown again.
Remove and delete secondary drive.
Remove first drive and add again with virtio controller.

2) Add virtio drivers to Windows Install media. I dont want to document this step by step.
Please read; https://pve.proxmox.com/wiki/Windows_guests_-_build_ISOs_including_VirtIO_drivers

3) Add a secondary cd drive to VM before installing and place the virtio iso to this one.
In install process load drivers from this drive and continue.
Shutdown after installing and delete secondary cdrom drive.

 

[NetRock]

Thank you for your kind help...

I thought what you were referring as follows:
Add SCSI drive, and then, use the virtio iso driver to install the driver
for SCSI controller from virtio iso. Something like the first way (above).

Sorry, I misunderstood ......