I recently got tired of the really slow I/O reads and latency (10-30 MB/s read, not sure for latency but very slow) from a provider I rent a virtual machine from. He uses freenas, the virtual machine runs on linux. I know this is normal speeds for most of what is offered out there, but that provider used to be the fastest I ever ran on, a bit slower then my 6 core 16gb ram and ssd drives home pc.
Last december we spent a couple of days testing things back and forth and got to maybe 20-35 MB/s.. But I gave up after few days because it didn't seem to get anywhere, and I wanted to do something else for christmas vacation.
He told me zfs was very good and it should run fine and perhaps faster.
I did not know much on zfs, but it felt odd that this would be an advantage after reading a bit on it. And know that I read much more on it and that I am testing it (thanks to ZoL), it brings me to this question:
Since zfs manages devices, filesystem, caching and much more.. isn't it useless or counter-productive to use zfs to host virtual machines, with vm's virtual devices being just a few (2-3) files on the zfs server?
It feels to me that only block level zfs features would be used. Might as well use lvm and give the full lvm device as virtual devices for the virtual machines. (mostly) Same block level features, no unneeded file operations, much more free memory on host and some more cpu.
Or did I get something wrong here.. ;)
