Using tools such as ionice inside guests

Emmanuel Lacour
2016-05-18T15:55:06Z

Dear kvm developpers/users,

I just saw that a change has been made in the kernel so the only one
scheduler available in guests for virtio-blk is now "none".

Seems introduced by [1].

I tried to used ionice on a 3.16 guest with virtio-blk and in fact it no
longer works because cfq is no longer available.

Is there a way to use, inside a guest, a tool like ionice to set
different IO priority in guests processes? It's very useful for loering
down the performance impact of backups jobs for example.

[1] -