Slow read from WinServer

[ThomasCZ]

Hi all,

I have a problem with the speed of reading data from Windows Server 2022 which is installed in Proxmox. I have done the VM setup step by step using the Wiki.

If I share a folder from the server, writing to it from another PC is no problem (about 100 MBps). But if I want to copy something from the folder to the PC, reading is terribly slow. Where could be the problem?

There is only a clean install on the server so far, without any other services.

agent: 1
bios: ovmf
boot: order=scsi0
cores: 2
cpu: x86-64-v2-AES
description: net0%3A virtio=BC%3A24%3A11%3ABD%3A64%3ABC,bridge=vmbr0,firewall=1
machine: pc-q35-8.1
memory: 16384
meta: creation-qemu=8.1.5,ctime=1716221295
name: WindowsServer
net0: virtio=BC:24:11:B9:BB:86,bridge=vmbr1,firewall=1
numa: 0
onboot: 1
ostype: win11
scsi0: local-lvm:vm-100-disk-0,cache=writeback,discard=on,size=100G
scsihw: virtio-scsi-pci
smbios1: uuid=7db106ab-0c2a-4cfa-be44-5c0ce181bfe9
sockets: 2
usb0: host=2-6
vcpus: 4
vmgenid: c6537e6c-42ca-4e78-bcbe-4a876418d210

 

[dietmar]

What exactly is terribly slow (what benchmark do you use)?

And what kind of network do you have (1Gbit)? What kind of disks do you use for the proxmox server (model, vendor)?

 

[ThomasCZ]

If I copy a file from PC to server, the speed is around 110 MB/s. If I copy a file from server to PC, the speed is unstable. For a while the file moves at 30 MB/s, but immediately the speed drops to maybe only 100 kB/s.

The network is not a problem. Because when I run iPerf from PC to server, the speed is around 960 Mb/s.

The disk in the server is HPE VK0480GEFJH

 

[deepcloud]

If I copy a file from PC to server, the speed is around 110 MB/s. If I copy a file from server to PC, the speed is unstable. For a while the file moves at 30 MB/s, but immediately the speed drops to maybe only 100 kB/s.

The network is not a problem. Because when I run iPerf from PC to server, the speed is around 960 Mb/s.

The disk in the server is HPE VK0480GEFJH

There is no problem.
its confussion of Bits and Bytes
Data transfer during copy is messured in Bytes - Big B.
Speed is messured in bits - small B
divide 960Mb/s by 8 to get the Bytes value = 120MB/s and you are getting 110 MB/s so its ok.

speed drop is a different problem and needs to be investigated - do a benchmark using - crystal disk mark inside the vm and report the score.
looks like you have a HPE SSD - so it should not be a problem.
you can also run iperf between 2 VM and check the network bandwidth

 

[leesteken]

If I copy a file from PC to server, the speed is around 110 MB/s. If I copy a file from server to PC, the speed is unstable. For a while the file moves at 30 MB/s, but immediately the speed drops to maybe only 100 kB/s.

Maybe the problem is on the other end (like a QLC SSD or SMR HDD)? What if you copy a file within the server or to another PC or to a RAM-drive?

 

[ThomasCZ]

Maybe the problem is on the other end (like a QLC SSD or SMR HDD)? What if you copy a file within the server or to another PC or to a RAM-drive?

When I try copying data from a second drive in the PC (HDD) to the system drive (SSD), the transfer speed is constant and around 100 MB/s (tested on a 4 GB file).

 

[ThomasCZ]

Now I tried to install a new VM with Win10 and copy the file from the server to the new VM.

 

[deepcloud]

View attachment 70253
Now I tried to install a new VM with Win10 and copy the file from the server to the new VM.

move the vm to a different disk - like the HDD and try to do the same there too and update us regarding the speed there

 

[ThomasCZ]

I have only one disk on the physical server

 

[deepcloud]

move the vm to a different disk - like the HDD and try to do the same there too and update us regarding the speed there

give the screenshot of - crystaldiskmark output in the vm

and hdparm -Tt /dev/sda

if you dont have hdparm do
apt install hdparm -y

 

[ThomasCZ]

give the screenshot of - crystaldiskmark output in the vm

and hdparm -Tt /dev/sda

if you dont have hdparm do
apt install hdparm -y

root@srv01:~# hdparm -Tt /dev/sda

/dev/sda:
Timing cached reads: 15896 MB in 2.00 seconds = 7958.06 MB/sec
Timing buffered disk reads: 1360 MB in 3.00 seconds = 453.18 MB/sec



Now I see that when I copy a file from the server, the ping is lost...

 

[deepcloud]

root@srv01:~# hdparm -Tt /dev/sda

/dev/sda:
Timing cached reads: 15896 MB in 2.00 seconds = 7958.06 MB/sec
Timing buffered disk reads: 1360 MB in 3.00 seconds = 453.18 MB/sec

View attachment 70254

Now I see that when I copy a file from the server, the ping is lost...

Hi Thomas,

Looks like your disk is ok, is inter vm copy on the same host ok ?
make a vm and try to copy within the vm's - it should be consistant at 100MBps approx as you have a 1Gbps card (without drops)

 

[ThomasCZ]

There is result robocopy form VM Win10:


There is result robocopy from PC Win10:
So fcking slow... about 5 minutes and still only 13%

and during robocopy the connection to the RDP server is slow and drops out. something must be wrong somewhere.

 

[_gabriel]

try with vdisk writecache to Default (None) + vcpu type as Host
+ what's server hw ? model , cpu , nic model

edit:

The network is not a problem. Because when I run iPerf from PC to server, the speed is around 960 Mb/s.

in both way ?

 

[ThomasCZ]

try with vdisk writecache to Default (None) + vcpu type as Host
+ what's server hw ? model , cpu , nic model

edit:

in both way ?

without any change :/ and yes, in both ways

This server:
HPE ProLiant ML110 Gen10 Silver 8-Core 2.10 GHz
1 x CPU Intel Xeon Silver 4208 8-Core 2.10 GHz 11M Cache
1 x 32 GB (2x 16 GB) DDR4
1 x 480 GB SSD 2.5" 6G SATA

 

[deepcloud]

without any change :/ and yes, in both ways

This server:
HPE ProLiant ML110 Gen10 Silver 8-Core 2.10 GHz
1 x CPU Intel Xeon Silver 4208 8-Core 2.10 GHz 11M Cache
1 x 32 GB (2x 16 GB) DDR4
1 x 480 GB SSD 2.5" 6G SATA

I don't know, but I hate the RAID Cards on HP Servers, they are bad in my view

 

[_gabriel]

HPE ProLiant ML110 are mainly distributed without RAID Card, only software fake raid like consumer motherboard.
Can be switched to regular ahci.

Another test to do , is plug another disk in the host, as a new LVM-Thin storage to store second vDisk for your VM, then test file copy within VM.