Am 22.02.2013 um 08:51 hat Peter Lieven geschrieben: > is there any project or plans to integrate a readcache in qemu either for > iscsi or for the whole block layer? > > I was thinking of 2 options: > a) assign (up to) a fixed amount of ram for readcaching of a VMs disk I/O. > Without SG_IO this seems > to be quite easy as there are only a handful of operations to intercept. > b) add SSDs to a Node and allow a VM to use up to X MB of that SSD as > read-cache. This should still be > a benefit if the storage for the VMs is on a NAS. > > I would like to do that independent of the OS for 2 reasons. First with iSCSI > the OS > is not involved. And second I would like to be able to add a memory limit for > the cache.
I'm not aware of any such plans, but if anyone wanted to write this, I think the right way to approach it would be as a new block driver that acts as a filter - for which we still don't have proper support, but if blkdebug/blkverify work, this could work as well. Kevin
