Cannot install any OS in Xen or KVM

[purevw]

I have used KVM on earlier machines, other than the one I am on. I prefer KVM over Xen, but have both installed. I have major sound system bugs in openSUSE if I boot into Xen.
Any time I try to install an OS (have tried Kali and LinuxMint), the install will partially complete, then the VM will freeze. The virt-manager shows that it is paused, but it is actually locked up tight. I have to force kill it. Once that is done, it is impossible to resume. Even though the install didn't complete, the bootloader is looking for a drive to boot from and ignoring the original install ISO file.
I do have virtualization enabled in BIOS and can find no other settings that might cause problems.
Machine is an ASUS ROG Strix X570-F motherboard with a Ryzen9 3900X CPU. I run 64GB of DDR4-2666 RAM. I allow anywhere from 4GB to 12GB of RAM to the VM, and allow 4 cores. With Ryzen9, 4 cores equates to 8 logical processors (threads). I have also tried manually selecting the number of sockets-cores-threads from the VM setup.
The only thing I noticed is that the RAM seems to max out during the install, regardless of the RAM allowed. The failure always occurs sometime after it is using near 100% RAM.

[guestfish]

I have used KVM on earlier machines, other than the one I am on. I prefer KVM over Xen, but have both installed. I have major sound system bugs in openSUSE if I boot into Xen.
Any time I try to install an OS (have tried Kali and LinuxMint), the install will partially complete, then the VM will freeze. The virt-manager shows that it is paused, but it is actually locked up tight. I have to force kill it. Once that is done, it is impossible to resume. Even though the install didn't complete, the bootloader is looking for a drive to boot from and ignoring the original install ISO file.
I do have virtualization enabled in BIOS and can find no other settings that might cause problems.
Machine is an ASUS ROG Strix X570-F motherboard with a Ryzen9 3900X CPU. I run 64GB of DDR4-2666 RAM. I allow anywhere from 4GB to 12GB of RAM to the VM, and allow 4 cores. With Ryzen9, 4 cores equates to 8 logical processors (threads). I have also tried manually selecting the number of sockets-cores-threads from the VM setup.
The only thing I noticed is that the RAM seems to max out during the install, regardless of the RAM allowed. The failure always occurs sometime after it is using near 100% RAM.

Ryzen CPU not friendly with qemu higher versions, i guess you are running qemu version 4.2.1 -> zypper info qemu. downgrade to 2.4. also virt-manager ram hungry! if you are installing kali then ram should higher than 4G.

[tsu2]

Although there might be issues running on a Ryzen processor, I don't track that so is a bit out of what I'm familiar with.

A few things you might want to try as general purpose "best pracitce"
- Ensure plenty of storage space in your storage pool. If on an SSD, "discard" aka "trim" your disk to ensure max available disk space available for use.
- If on a brand new machine, run some tests, perhaps stress test some benchmarking to verify your disk performance. If on an HDD (not SSD) you ca even move (not copy) a few large files to and from the disks.
- If this is on storage that has been used a long time, defrag your disk files periodically. Short of running a defrag utility, you can move files completely off the partition to temporary storage and move back again. The move operation to a different partition essentially deletes the file fragments from the disk and when you re-write, re-organize and write as efficiently as possible. Note that this is mainly for optimizing I/O and general compaction so that a new Guest disk file has fewer fragments.
- If you're familiar with the boot process, it may be important to identify at what Installation step it freezes. It can matter if for instance, the problem might be during preparing the disk layout or device detection or application writing, and if a specific error is thrown like a "network unavailable" or "file not found" error is thrown.
- No matter your hardware resources available and for all virtualization technologies, set up your new Guest as follows... Of course, you can change the values later after installation
2 CPU, 1 core each
4GB RAM
Enable nested virtualization only if you intend to use it.

Remember, each of the above settings are only presented to the Guest environment, and the system can re-configure to adapt to any changes on each bootup. And, none of those settings has much to do with how those resources actually run on the HostOS.

- If you have any other services running on the same HostOS/physical machine, monitor closely so that there isn't disk I/O contention. A useful utility you can run is iotop.

HTH,
TSU

[purevw]

Although there might be issues running on a Ryzen processor, I don't track that so is a bit out of what I'm familiar with.

A few things you might want to try as general purpose "best pracitce"
- Ensure plenty of storage space in your storage pool. If on an SSD, "discard" aka "trim" your disk to ensure max available disk space available for use.
- If on a brand new machine, run some tests, perhaps stress test some benchmarking to verify your disk performance. If on an HDD (not SSD) you ca even move (not copy) a few large files to and from the disks.
- If this is on storage that has been used a long time, defrag your disk files periodically. Short of running a defrag utility, you can move files completely off the partition to temporary storage and move back again. The move operation to a different partition essentially deletes the file fragments from the disk and when you re-write, re-organize and write as efficiently as possible. Note that this is mainly for optimizing I/O and general compaction so that a new Guest disk file has fewer fragments.
- If you're familiar with the boot process, it may be important to identify at what Installation step it freezes. It can matter if for instance, the problem might be during preparing the disk layout or device detection or application writing, and if a specific error is thrown like a "network unavailable" or "file not found" error is thrown.
- No matter your hardware resources available and for all virtualization technologies, set up your new Guest as follows... Of course, you can change the values later after installation
2 CPU, 1 core each
4GB RAM
Enable nested virtualization only if you intend to use it.

Remember, each of the above settings are only presented to the Guest environment, and the system can re-configure to adapt to any changes on each bootup. And, none of those settings has much to do with how those resources actually run on the HostOS.

- If you have any other services running on the same HostOS/physical machine, monitor closely so that there isn't disk I/O contention. A useful utility you can run is iotop.

HTH,
TSU

Thank you. guestfish may be correct that there are issues with certain Ryzen processors, however I am not willing to regress Virt-manager back to a version from years ago, assuming I can even find version 2 in a 15.2 repo. My M.2 SSD is only 20% utilized and can write well over 1GB per second. With Handbrake, I can generally transcode Blu-ray content at 3X speed, so I don't believe that power is the issue. As a test, I installed Kali in an openSUSE 15.2 low spec laptop and had no problems.
I can try your suggestions over the weekend and report back. If I set VM for 2 CPUs with one core each, it would still offer 4 logical processors to the guest. as each Ryzen core runs 2 threads. Is that what you intended, or should I limit it to two logical processors?
There is no exact point of the install where failure occurs. I have tried both Kali Linux and linuxmint. They each stop responding at random times during the install. The only common denominator seems to be that Virt-manager has shown 100% RAM usage for several seconds, up to a full minute or two, before the failure. It even did so when I was allowing 12GB of RAM to the guest, which I find hard to accept. On my laptop, I allowed 4GB. It maxed out during install, but did not fail. I will try to experiment over the weekend with it.

[guestfish]

Thank you. guestfish may be correct that there are issues with certain Ryzen processors, however I am not willing to regress Virt-manager back to a version from years ago, assuming I can even find version 2 in a 15.2 repo. My M.2 SSD is only 20% utilized and can write well over 1GB per second. With Handbrake, I can generally transcode Blu-ray content at 3X speed, so I don't believe that power is the issue. As a test, I installed Kali in an openSUSE 15.2 low spec laptop and had no problems.
I can try your suggestions over the weekend and report back. If I set VM for 2 CPUs with one core each, it would still offer 4 logical processors to the guest. as each Ryzen core runs 2 threads. Is that what you intended, or should I limit it to two logical processors?
There is no exact point of the install where failure occurs. I have tried both Kali Linux and linuxmint. They each stop responding at random times during the install. The only common denominator seems to be that Virt-manager has shown 100% RAM usage for several seconds, up to a full minute or two, before the failure. It even did so when I was allowing 12GB of RAM to the guest, which I find hard to accept. On my laptop, I allowed 4GB. It maxed out during install, but did not fail. I will try to experiment over the weekend with it.

actually, resource allocation up to you, no matter. depends what instance you are going to run. heavy instance require more resource. i am mentioned qemu version not virt-manager version, its different things. if ryzen cpu gives you such a problems, you need to check 2 things: qemu version (ryzen cpu not ok with with latest qemu versions, ok with version 2) 2. /sys/module/kvm_intel/parameters/nested or /sys/module/kvm_amd/parameters/nested -> be sure that you have folder named kvm_amd not kvm_intel and nested should be Y.

[tsu2]

Thank you. guestfish may be correct that there are issues with certain Ryzen processors, however I am not willing to regress Virt-manager back to a version from years ago, assuming I can even find version 2 in a 15.2 repo. My M.2 SSD is only 20% utilized and can write well over 1GB per second. With Handbrake, I can generally transcode Blu-ray content at 3X speed, so I don't believe that power is the issue. As a test, I installed Kali in an openSUSE 15.2 low spec laptop and had no problems.
I can try your suggestions over the weekend and report back. If I set VM for 2 CPUs with one core each, it would still offer 4 logical processors to the guest. as each Ryzen core runs 2 threads. Is that what you intended, or should I limit it to two logical processors?
There is no exact point of the install where failure occurs. I have tried both Kali Linux and linuxmint. They each stop responding at random times during the install. The only common denominator seems to be that Virt-manager has shown 100% RAM usage for several seconds, up to a full minute or two, before the failure. It even did so when I was allowing 12GB of RAM to the guest, which I find hard to accept. On my laptop, I allowed 4GB. It maxed out during install, but did not fail. I will try to experiment over the weekend with it.

My CPU/core recommendation is only to be conservative during installation. Multiple cores probably have minimal benefit during installation anyway because nearly everything is a serial flow, there is little opportunity for extensive parallelism. After you've installed, you can re-configure resources to anything you wish and Linux will pick up the changes on boot.

TSU