Re: [CentOS-virt] KVM virtio block layer - is TRIM/DISCARD supported?

On Sat, Feb 2, 2013 at 5:12 AM, Dmitry E. Mikhailov d.mikhailov@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.