On Sat, Feb 2, 2013 at 5:12 AM, Dmitry E. Mikhailov <d.mikhailov at infocommunications.ru> wrote: > Hi, > > One question please: > > If I use SSD as a storage on a host machine, does KVM's virtio I/O layer > pass the TRIM/DISCARD commands to the SSD? Doesn't look like it, *yet*. That looks like it came out in the 2.6.33 kernels, the upstream vendor for CentOS has only gotten up to 2.6.32. I wouldn't necessarily call it stable for production use until it's been out for a while. > > I guess the question would be twofold: > 1) is TRIM supported/forwarded if only one LVM'ed partition of SSD is > forwarded? > 2) is TRIM supported/forwarded if full SSD is forwarded (i.e. /dev/sdX) See above.