Ceph » CephFS

On Mon, 6 Dec 2010, Jim Schutt wrote:

Hi Sage,

On Sat, 2010-12-04 at 21:59 -0700, Sage Weil wrote:

Also, a possibly related behavior I've noticed is that
an 'ls' on a directory where I'm writing files
does not return until all the writers are finished.

I realize it's likely related to caps, but
I'm hoping that can be fixed up somehow?

It depends. If the clients "wrote" that data into the buffer cache and
it's just taking a long time to flush it out, then things are working as
intended (given current locking state machine). That can be improved, but
hasn't been a priority (see #541). If the dd's are still writing and they
don't stop, something is wrong, either on the mds or kclient.

So here's the results from a couple trials. In the
below results, "do_pdd" is a simple wrapper around
"pdsh -w <clients> dd" that computes aggregate
results.

In one window I launch the parallel dd commands;
in another window, on a client of my filesystem,
I do the ls.

This is possibly related to #325.