Ceph » RADOS

As describe in ceph-dev mail list:
"scubbing for a long time and not finished"

I find a pg on my test cluster in doing scrubbing for a long time
and not finish. there are not some useful scrubbing log. scrubs_active
is 1, so inc_scrubs_pending return false. I think the reason is that
some scrub message is lost, so primary can not continue chunky_scrub ,
so it hang up at scrubbing.

Currently, users do not know when some pg do scrubbing for a long time(defined as osd_scrub_max_time).
I think whether we could give some warming if it happend. It would tell the user something may be wrong in cluster.

To give this warning message, we also should add last_scrub_start_stamp for pg_stat_t.