disk monopolized?
Last night I was "optimizing" a qcow2 virtual image
(after zero filling the free space), running (as root):
qemu-img convert -f qcow2 -O qcow2 old.img new.img
The copying and scanning for zero blocks pretty
much took over the disk. Anything else I tried to run
which needed access to something on that disk would
hang for minutes at a time before getting through.
Is that normal behavior? I thought folks were supposed
to take turns and play nice together :-).