[ovirt-users] moving disk failed.. remained locked

[David Teigland]

On Thu, Feb 23, 2017 at 08:11:50PM +0200, Nir Soffer wrote:
> > [g.cecchi at ovmsrv05 ~]$ sudo sanlock client renewal -s
> > 922b5269-ab56-4c4d-838f-49d33427e2ab
> > timestamp=1207533 read_ms=2 write_ms=0 next_timeouts=0 next_errors=0
> > timestamp=1207554 read_ms=2 write_ms=0 next_timeouts=0 next_errors=0
> > ...
> > timestamp=1211163 read_ms=2 write_ms=0 next_timeouts=0 next_errors=0
> > timestamp=1211183 read_ms=2 write_ms=0 next_timeouts=0 next_errors=0
> > timestamp=1211204 read_ms=2 write_ms=0 next_timeouts=0 next_errors=0
> >
> > How do I translate this output above? What would be the difference in case
> > of problems?
> 
> David, can you explain this output?
> 
> read_ms and write_ms looks obvious, but next_timeout and next_errors are
> a mystery to me.

Sorry for copying, but I think I explained it better then than I could now!
(I need to include this somewhere in the man page.)

commit 6313c709722b3ba63234a75d1651a160bf1728ee
Author: David Teigland <teigland at redhat.com>
Date:   Wed Mar 9 11:58:21 2016 -0600

    sanlock: renewal history
    
    Keep a history of read and write latencies for a lockspace.
    The times are measured for io in delta lease renewal
    (each delta lease renewal includes one read and one write).
    
    For each successful renewal, a record is saved that includes:
    - the timestamp written in the delta lease by the renewal
    - the time in milliseconds taken by the delta lease read
    - the time in milliseconds taken by the delta lease write
    
    Also counted and recorded are the number io timeouts and
    other io errors that occur between successful renewals.
    
    Two consecutive successful renewals would be recorded as:
    
    timestamp=5332 read_ms=482 write_ms=5525 next_timeouts=0 next_errors=0
    timestamp=5353 read_ms=99 write_ms=3161 next_timeouts=0 next_errors=0
    
    timestamp is the value written into the delta lease during
    that renewal.
    
    read_ms/write_ms are the milliseconds taken for the renewal
    read/write ios.
    
    next_timeouts are the number of io timeouts that occured
    after the renewal recorded on that line and before the next
    successful renewal on the following line.
    
    next_errors are the number of io errors (not timeouts) that
    occured after renewal recorded on that line and before the
    next successful renewal on the following line.
    
    The command 'sanlock client renewal -s lockspace_name' reports
    the full history of renewals saved by sanlock, which by default
    is 180 records, about 1 hour of history when using a 20 second
    renewal interval for a 10 second io timeout.
    
    (A --summary option could be added to calculate and report
    averages over a selected period of the history.)