July 20, 20241 yr Hi guys Looking for some advice. My server is based on a Ryzen 5900x with 12 cores (+12). I have a Windows 11 VM running on my server for my wife to use for her business. Everything works great except during boot. So during boot the vm will only use one core. As soon as windows has booted to logon screen it suddenly starts using the 16 cores I have assigned. The problem is the vm boots very slow because of this. I have tried to search for a solution, but obviously not finding anything - or I am completely missing something. I have been using unraid for some time now, but still consider myself a noob. Appreciate any help.
July 20, 20241 yr Reduce the core assignment to a single core, start with the highest number core, and reduce the RAM max to 4GB. Test. Add another core, test. When the VM stops feeling faster with each addition, keep that number of cores and increase RAM by 2GB, test and repeat. VM's typically perform best with much less assigned than seems intuitive.
July 21, 20241 yr Author Hi, thanks for your time. Performance of the vm is very good. I just don't know why it uses only one core for the whole boot process, as soon as the login on windows appears it immediately moves to use all assigned cores. During boot that 1 core is at 100% and boot takes long because - well only one core is used.
July 21, 20241 yr 13 hours ago, Karl Strachan said: During boot that 1 core is at 100% and boot takes long because - well only one core is used. You missed my point. If you actually go through with my proposed experiment, you will probably see that boot times are significantly faster with fewer resources bound exclusively to the VM. Any resources bound to the VM are unavailable for the host, meaning the virtual motherboard that the VM is running is crippled. Slow virtual motherboard = slow I/O = slow boot times, and well as sub-optimal load times as the VM needs to fetch data from the vdisk. Keep in mind that the CPU usage graph in Unraid includes IOWait, so what you are seeing is the slowness of the data being read from the vdisk into RAM as the guest boots. Give the host more resources so it can feed the VM faster.
July 21, 20241 yr Author I get what you are saying, but is it not strange that all the other cores are doing nothing during boot? I feel like that is the reason for slow boot. It would surely boot faster if it used more than one core during boot? I just don't understand why it would max out 1 core while all the others assigned to the vm are at idle. My homeassistant VM uses all the cores assigned while it boots. I hope I am getting my point across. I have tried what you suggested with no difference. Only one core gets utilized during boot no matter.
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