ZFS L2arc 16.0E size

[Slawa Olhovchenkov]

On Mon, Feb 23, 2015 at 11:31:34PM +0100, Frank de Bot (lists) wrote:

> Slawa Olhovchenkov wrote:
> > On Mon, Feb 23, 2015 at 12:21:35AM +0300, Slawa Olhovchenkov wrote:
> > 
> >> On Mon, Feb 16, 2015 at 12:52:17AM +0000, Steven Hartland wrote:
> >>
> >>> IIRC this was fixed by r273060, if your remove your cache device and 
> >>> then add it back I think you should be good.
> >>
> >> r273060 will be reverted.
> >> I am use stable (r276179) and still have (partialy) this problem:
> >>
> >> cache                                       -      -      -      -      -      -
> >>   ada0                                   477G   477G  16.0E         -     0%   100%
> >>   ada1                                   477G   477G  16.9M         -     0%    99%
> >>   da2                                    477G   477G  25.0M         -     0%    99%
> >>   da3                                    477G   477G  14.6M         -     0%    99%
> >>   da4                                    477G   477G  30.6M         -     0%    99%
> >>   da5                                    477G   477G  15.0M         -     0%    99%
> >>   da6                                    477G   477G   298K         -     0%    99%
> >>   da7                                    477G   477G  18.2M         -     0%    99%
> > 
> > same server, some time late:
> > cache                                       -      -      -      -      -      -
> >   ada0                                   477G   477G  16.8M         -     0%    99%
> >   ada1                                   477G   477G  32.1M         -     0%    99%
> >   da2                                    477G   477G  5.70M         -     0%    99%
> >   da3                                    477G   477G  16.0E         -     0%   100%
> >   da4                                    477G   477G  26.1M         -     0%    99%
> >   da5                                    477G   477G  26.6M         -     0%    99%
> >   da6                                    477G   477G  16.0E         -     0%   100%
> >   da7                                    477G   477G  16.0E         -     0%   100%
> > 
> > hmm, -p don't affect -v values.
> 
> Tonight I had run some tests:
>  - Disabling compression (by changing ZIO_COMPRESS_LZ4 to
> ZIO_COMPRESS_OFF in sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c
> in l2arc_compress_buf
>  - disabling trim by vfs.zfs.trim.enabled=0 in loader.conf
>  - trying to prevent io queues, but I don't think this was good. I  was
> thinking there maybe is a possibility that between filling a writebuffer
> for a vdev the size of l2arc was checked, but didn't take in account
> that not all data is there (I really don't have a clue if  this makes
> any sense)
> 
> None of these test were successful, every time free space is 16.0E and
> used space keeps on growing and growing.
> 
> Slawa, I do notice that first ada0 was at 16.0E, but at your second post
> not anymore.

Yes, I see too and do second post for this.
I think this is may be error on output (not for internal structure as
past), but -p key don't work for this values and I can't recalculate
bu hands.