The configuration is: A linux server and a nas box (netgear) acting as nfs server.
It is easy for a single process on the linux server to use all i/o bandwidth by simply copying a file from the nfs share to the nfs share. The i/o channel is jammed and all other processes on the server will nearly halt waiting for i/o. Load grows up to 10-20 (four cores), more and more pdflush processes appear... until someone stopps the file copy.
How can I limit the i/o bandwidth the cp process uses?
nice will not help of course, but also
ionice -c3 has no effect. Does ionice affect nfs mounts at all? Is there something like nfsnice ?