Windows 10 VM - Stuttering when reading/writing files

[Brad]

I'm experiencing a strange issue where transferring files within my Windows 10 VM from a Share causes the VM to stutter, meaning the cursor no longer moves smoothly and the entire OS is prone to freezing momentarily. When the file transfer finishes everything goes back to normal (working perfectly).

 

My issue is related to this: 

 

but the whole system doesn't lock up, only the VM freezes/hangs.

 

I've tried increasing "md_num_stripes" to 8192 (mentioned in the Tips and Tweaks Wiki - https://wiki.lime-technology.com/Tips_and_Tweaks) as this seemed to be the same issue I'm experiencing, but it hasn't helped unfortunately.

 

I'm running unRAID version 6.4.0-rc10b.

 

I've attached my diagnostics file, let me know if you need anything else (ie, the VM XML?). Many thanks.

tower-diagnostics-20171110-1217.zip

Edited November 10, 2017 by Brad

[Brad]

The cause of the stutter/hang does appear to be due to file transfers causing 100% load on the VM CPU 1, please see the attached screenshot which shows this.

 

 

File transfers are around 18-20MB/s.

 

If I copy files via SSH directly on the Unraid server from one HDD to another HDD on the array, this works fine. There's no lag within the VM and the transfer speeds are mostly 100MB/s or above. Obviously because I'm using a vdisk file for the VM I can't just use SSH as a workaround and transferring files to/from the VM within Windows is painful.

 

I can't figure out what's causing this. Any ideas?

 

EDIT: Transferring files on a CentOS VM works fine. I'll try installing another Windows 10 VM now to rule that out.

Edited November 12, 2017 by Brad

[Brad]

OK, I've installed another fresh Windows 10 VM using Q35-2.10 (instead of i440fx-2.10) and this is working fine. Unless the different machine type solved it, something is obviously incorrectly configured/broken on the other VM.

 

File transfers from the array on the new VM are fast (100MB/s+) and most importantly it doesn't cause any hangs/stutters. Also audio has improved as I get no crackling now at all - at the moment everything is working perfectly.

 

I'm not sure what's wrong with the other VM and I doubt I'll try to fix it now. If anyone has any ideas I would be very interested!

[loglud]

I would highly recommend looking through https://forums.lime-technology.com/topic/47345-performance-improvements-in-vms-by-adjusting-cpu-pinning-and-assignment/. 

 

In it the isolation of the CPU threads should help you.

[Brad]

I did isolate the CPUs and pinned them to the VM (and used emulatorpin) but it didn't resolve the issue I was experiencing with file transfers unfortunately. The VM still lagged whenever transferring a file from the array to the VM.

 

I suspect the actual VM is misconfigured in some way.

[hblockx]

I just noticed you have the same issue...

 

[xxxliqu1dxxx]

Hi - sorry for resurrecting an old thread, but I am having a very similar issue. Creating a VM from scratch, with Q35 did not fix it for me... Could you confirm if there was something else to check? Thanks in advance.