[SOLVED] Change VM virtio0 to scsi0 to enable SSD emulation

[pizza]

I have migrated older VM Ubuntu machines to a thin-LVM storage. To make fstrim work (enabling SSD emulation), the virtio0 disk must changed to scsi0. I editted the VM conf file, but the VM will not start because the disk is not found.

 

[leesteken]

For trim to work, you don't need SSD emulation but you need to enable the Discard option for the virtual drive (and setup trim/discard inside the VM of course).
"on VirtIO Block drives is only supported on guests using Linux Kernel 5.0 or higher", according to the documenation. How old is your Ubuntu?

 

[pizza]

Ubuntu 18.04 with kernel 4.15

For trim to work, you don't need SSD emulation but you need to enable the Discard option for the virtual drive (and setup trim/discard inside the VM of course).
"on VirtIO Block drives is only supported on guests using Linux Kernel 5.0 or higher", according to the documenation. How old is your Ubuntu?

Ubuntu 18.04 with kernel 4.15, discard is enabled

 

[pizza]

Update: Installing kernel 5.4 on Ubuntu 18.04 makes fstrim working

https://ubuntuhandbook.org/index.php/2020/08/ubuntu-18-04-5-released-5-4-kernel/