Re: Windows 11 KVM guest IO Performance

[Linux-Fan]

basti writes:

Am 28.11.24 um 13:01 schrieb basti:

I have move a Win10 KVM guest to new hardware and than upgrade this guest to Windows 11.

[..]

4x qemu64 CPU (1 Socket/ 4 Core/ 1 Threads)
8GB RAM
No graphic tablet
No Ballon driver

When I copy a big file (~8GB) from Network to local I get 1 GBit/s speed.



Any ideas or suggestions?

When I run to install RSAT tools or ClearMgr I only see 10-25 MB/s in iostat on the KVM host.

The disk use Virtio driver with no buffer and unmap.

Three ideas:

1. Check the status of the virtual drive from Windows point of view:
   Open the “Optimize Drives” application and verify that the
   Media type equals “Thin provisioned device” (it should say that).

2. `qemu64` may be an inadquate choice of CPU.
   See 
<https://www.berrange.com/posts/2018/06/29/cpu-model-configuration-for-qemu-kvm-on-x86-hosts/>
   for some ideas about what to chose instaed. Note that it may
   cause issues with Windows Activation i.e. if you don't have
   the necessary data at hand, maybe don't just change it on a
   whim.

3. Does the VM behave notably slower than a comparable reference
   system?`I am asking because IMHO it may very well be a reasonable
   IO throughput for a Windows OS and maybe there is nothing out of
   the ordinary I/O-wise here?

   For comparison, I ran the `cleanmgr` and deleted about 4 GiB of
   files from my Windows 11 VM just now and it never exceeded ~9 MiB/s
   (measuring in 10sec intervals I got 90 MiB/interval)
   on the host averaging much below.

HTH
Linux-Fan

öö

pgpM7exiUuyLV.pgp
Description: PGP signature