[pve-devel] firsts cache benchs results

[Dietmar Maurer]

> rbd
> ------------------
> default: 6000
> cache=none : 6000
> cache=writeback : 7000

from qemu-kvm/block/rbd.c:
--------------------
    if (flags & BDRV_O_NOCACHE) {
        rados_conf_set(s->cluster, "rbd_cache", "false");
    } else {
        rados_conf_set(s->cluster, "rbd_cache", "true");
-------------------

They also suggest to use writeback, so that should be default for rdb.

> sheepdog
> ------------------
> default: 300
> cache=none : 300
> cache=writeback : 300

Sheepdog ignores the BDRV_O_NOCACHE flag.

see qemu-kvm/block/sheepdog.c