File changes propagating in older snapshots: what am I doing wrong?

[Tomohiro Kusumi]

A slave PFS doesn't even have a PFS root inode till it's once sync'd
with a master.
Until then one can't really do anything with it (can't even cd), but
no document explains this.

http://lists.dragonflybsd.org/pipermail/users/2015-April/311953.html

2017-04-08 20:59 GMT+03:00 Matthew Dillon <dillon at backplane.com>:
> 0x0000000000000000 is not a valid transaction id.  Not sure how it wound up
> in the snapshot list but that slave has not been synchronized from a master
> yet and until it is there is no real snapshot.
>
> -Matt
>
> On Sat, Apr 8, 2017 at 9:55 AM, <tech_lists at mail.com> wrote:
>>
>> Hi,
>>
>> I have other information.. the behavior started to be 100% reproducible on
>> my machine: every time I added a file I found it in the past snapshot. But
>> it appeared after a delay, ranging from 1 to about 20 seconds!
>>
>> % hammer snapls /home/attic/
>> Snapshots on /home/attic/       PFS#2
>> Transaction ID          Timestamp               Note
>> 0x0000000000000000      2017-04-06 09:57:34 CEST        -
>>
>> % pwd
>> /home/attic
>>
>> % touch a_new_file
>> % ls .@@0x0000000000000000
>> disk_stats.txt
>>
>> The file isn't in the snapshot yet. But if a i keep repeating the ls
>> command after a few seconds I find it:
>>
>> % ls .@@0x0000000000000000
>> a_new_file      disk_stats.txt
>>
>>
>> Then I decided to run hammer cleanup:
>>
>> # hammer cleanup
>> [... Output snipped ...]
>> cleanup /home/attic          - handle PFS#2 using /var/hammer/home/attic
>>            snapshots - run
>>                prune - run
>>            rebalance - run..
>>              reblock - run....
>>               recopy - skip
>> [... Output snipped ...]
>>
>> Now I have a new snapshot but the old snapshot is gone:
>>
>> % hammer snapls /home/attic/
>> Snapshots on /home/attic/       PFS#2
>> Transaction ID          Timestamp               Note
>> 0x00000001186c2200      2017-04-08 18:25:50 CEST        -
>>
>> This new snapshot doesn't exhibit the behavior described above: I can add
>> and delete files in the main directory and the snapshot doesn't change.
>>
>> Sadly, now I have no access to the old snapshot to further diagnose the
>> problem. I didn't think hammer cleanup would delete a snapshot from two days
>> ago.
>>
>>
>> Kind regards,
>> Andrea
>>
>>
>>
>