[OpenIndiana-discuss] All of a sudden I'm feeling stupid.... Where does the COW and the newly written data go for snapshots?

[Hans J. Albertsson]

noatime, isn't that a UFS specific mount option??

Can this be done in mount_nfs??

On 2015-05-13 21:36, David Brodbeck wrote:
> On Wed, May 13, 2015 at 4:33 AM, Udo Grabowski (IMK) <udo.grabowski at kit.edu>
> wrote:
>
>> On 13/05/2015 09:20, Hans J. Albertsson wrote:
>>
>>> This is what it looks like on the FreeNAS box
>>>
>>> NAME                             AVAIL   USED  USEDSNAP  USEDDS
>>> USEDREFRESERV  USEDCHILD
>>> Tank/cifs                        8.93T  1.45T     9.18M
>>> 1.45T              0          0
>>> Tank/cifs at transfer_prep              -  8.24M         - -
>>> -          -
>>> Tank/cifs at transfer1                  -   966K         - -
>>> -          -
>>> Tank/cifs at now                        -      0         - -
>>> -          -
>>> Tank/cifs at auto-20150513.0100-2w      -      0         - -
>>> -          -
>>>
>>> I'd like to see what data is to blame for the 966K reported for
>>> transfer1 as "USED"
>>>
>> These are usually access time updates, since the snapshot preserves
>> access times. We have a few Megs each day on heavily accessed data.
>
> If you can mount the filesystem 'noatime', that would clear it up pretty
> quickly.  I generally do this as a matter of course, these days -- very few
> things need atimes and the penalty of adding a write to every read isn't
> worth it.  The only things I can think of offhand that might need atime are
> mail spools and NNTP.
>