Hi.
I migrated a physical server to Proxmox 8.2.4 about 10 days ago. I have just logged in to it today to do some maintenance on some installed software, and found it to be extremely slow. Even the spinny-hourglass is slow, and switching tabs in task manager.
This is running on the same host as a couple of other Server 2022 guests, and couple of Linux guests.
What is strange, is that another VM running Windows Server 2022 with 4gb RAM and 2 cores on the same host, is showing 10x faster CPU throughput than the problem guest. The problem guest is on the same host, and has 8 assigned cores and 32gb RAM.
The only obvious difference in configuration is that the slow machine has 'threads' for disks and 'disk cache: none', while the others have io_uring and write back. I changed the cache configuration because I was working to try to resolve the IO freeze issue as per this epic github issue. (I was seeing some freeze-up while waiting for event log to load at the same time as a Windows Update installing, and I could see 'request was re-tried on disk blah' in the event log - which is not good.
Also, the bad one has ostype=win11 (which is supposed to be correct for Server 2022), and the non-bad one has ostype=win10.
Note I have another (third, not documented below) Server 2022 guest running SAP B1 and SQL Server 2019 and that is performing fine too. That has ostype=win11, writeback, io_uring, and disks are attached as scsi0 and scsi1.
This is the config of the machine that is running like a pig right now. It is a file server. I will reboot it out of hours tonight.
This is the config of the other machine which only has 2 CPU cores assigned, and is running fine. Check out the CPU-Z benchmark screenshots coming up next..
Here is the slow machine showing system information and a CPU-Z bench:
and here is the fast / normal machine:
Any ideas?
Thanks,
Carl
I migrated a physical server to Proxmox 8.2.4 about 10 days ago. I have just logged in to it today to do some maintenance on some installed software, and found it to be extremely slow. Even the spinny-hourglass is slow, and switching tabs in task manager.
This is running on the same host as a couple of other Server 2022 guests, and couple of Linux guests.
What is strange, is that another VM running Windows Server 2022 with 4gb RAM and 2 cores on the same host, is showing 10x faster CPU throughput than the problem guest. The problem guest is on the same host, and has 8 assigned cores and 32gb RAM.
The only obvious difference in configuration is that the slow machine has 'threads' for disks and 'disk cache: none', while the others have io_uring and write back. I changed the cache configuration because I was working to try to resolve the IO freeze issue as per this epic github issue. (I was seeing some freeze-up while waiting for event log to load at the same time as a Windows Update installing, and I could see 'request was re-tried on disk blah' in the event log - which is not good.
Also, the bad one has ostype=win11 (which is supposed to be correct for Server 2022), and the non-bad one has ostype=win10.
Note I have another (third, not documented below) Server 2022 guest running SAP B1 and SQL Server 2019 and that is performing fine too. That has ostype=win11, writeback, io_uring, and disks are attached as scsi0 and scsi1.
This is the config of the machine that is running like a pig right now. It is a file server. I will reboot it out of hours tonight.
Bash:
root@pve2:~# qm config 203
agent: 1
balloon: 0
bios: ovmf
boot: order=scsi0;ide0;ide2;net0
cores: 8
cpu: host
efidisk0: raid5_11tb:vm-203-disk-0,efitype=4m,pre-enrolled-keys=1,size=4M
ide0: none,media=cdrom
ide2: local:iso/virtio-win-0.1.248.iso,media=cdrom,size=715188K
machine: pc-q35-9.0
memory: 32768
meta: creation-qemu=9.0.0,ctime=1722194489
name: SVR2
net0: virtio=BC:24:11:A2:23:70,bridge=vmbr0
numa: 0
onboot: 1
ostype: win11
scsi0: raid5_11tb:vm-203-disk-3,aio=threads,discard=on,iothread=1,size=400G
scsi1: raid5_11tb:vm-203-disk-4,aio=threads,discard=on,iothread=1,size=16G
scsi2: raid5_11tb:vm-203-disk-5,aio=threads,discard=on,iothread=1,size=4000G
scsihw: virtio-scsi-single
smbios1: uuid=bdab8c7e-c806-42a2-9499-d10e25203ef1
sockets: 1
tpmstate0: raid5_11tb:vm-203-disk-1,size=4M,version=v2.0
vmgenid: 2fc4c357-0562-4848-b829-6d5d6aeec8d1
This is the config of the other machine which only has 2 CPU cores assigned, and is running fine. Check out the CPU-Z benchmark screenshots coming up next..
Bash:
root@pve2:~# qm config 201
balloon: 0
bios: ovmf
boot: order=sata3
cores: 2
cpu: host
efidisk0: raid5_11tb:vm-201-disk-0,efitype=4m,pre-enrolled-keys=1,size=4M
ide0: local:iso/virtio-win-0.1.248.iso,media=cdrom,size=715188K
machine: pc-q35-8.1
memory: 4096
meta: creation-qemu=8.1.5,ctime=1715097795
name: SVR1
net0: virtio=BC:24:11:1B:00:E2,bridge=vmbr0
numa: 0
onboot: 1
ostype: win10
sata3: raid5_1.8tb:vm-201-disk-3,cache=writeback,discard=on,size=128G,ssd=1
scsihw: virtio-scsi-single
smbios1: uuid=6c785c5b-7242-4c6c-a9fc-4b59496258f3
sockets: 1
tpmstate0: raid5_11tb:vm-201-disk-1,size=4M,version=v2.0
vmgenid: 8ce4931a-1466-4c20-97a8-b3e7d12e318d
Here is the slow machine showing system information and a CPU-Z bench:
![slow.png](https://internetsomething.com/kvmslow/slow.png)
and here is the fast / normal machine:
![fast.png](https://internetsomething.com/kvmslow/fast.png)
Any ideas?
Thanks,
Carl
Last edited: