iostat can be a bit special.I -think- under linux its the amount
of time spent waiting for pending disk IO to complete. Now,
some chipsets and their drivers seem to spend a lot of time in IOWAIT
compared to others. The traditional difference was polled vs dma'ed
disk IO - with polled IO, the
On Fri, Oct 10, 2008, Adrian Chadd wrote:
Now, you could go groveling through the kernel to try and figure out
whether IOWAIT includes nfs activity (which I believe would be
the disk IO related to NFS, but it could be other things I guess) and
first see if doing userspace disk IO does a lot
On Fri, Oct 10, 2008 at 05:50:52AM +0800, Adrian Chadd wrote:
I've never seen IOWAIT for NFS client traffic (ie, traffic from an
NFS client talking to an NFS server) but who knows, this is linux..
I would say this doesn't count to iowait either; see
fs/nfs/pagelist.c:nfs_wait_on_request() -- it
Grant Street wrote:
I have a machine with a good proportion of IOWait 20-30%. It does have
local disks and it performs operations on NFS mounts. I just wanted to
be sure if IOWait includes NFS activity or not. I also want a way if it
is NFS to be able to say for sure if it is a bottleneck on
