On Wed, 13 Aug 2014 10:05:51 +0400 Michael Tokarev <m...@tls.msk.ru> wrote:
> BTW, I found a system here with an SSD which supports discard, and tried my > guests against it -- everything works fine when I use sata/ahci, but it breaks > indeed when using the default IDE interface. Hello, Thanks for working on this! Sorry for not being able to test an updated version sooner. Something to note, you do not need any TRIM-capable hardware such as SSD on the host to take advantage of TRIM passthrough. Just place the RAW format VM disk image on any filesystem which supports sparse files (e.g. Ext4 or Btrfs), and when the guest system issues a TRIM, when using "discard=unmap" the VM image file will be "re-sparsifyed" on the host filesystem, deallocating all the TRIMed areas from disk storage, in effect it will take much less space on disk than before: http://s.lowendshare.com/7/1407910491.666.2014-07-16T130602Z-trim.png I was only successful in using this with the virtual IDE interface disks on Qemu/KVM 2.0, the virtio mode does not seem to support TRIM; did not try with sata/ahci. -- With respect, Roman
signature.asc
Description: PGP signature