PFS mirror problems

Tomohiro Kusumi kusumi.tomohiro at
Wed Aug 24 06:14:29 PDT 2016

I first saw this in 2014 when I first used DragonFly (I think 3.8).
It happened without upgrade or downgrade of PFS.

Unmounting once and then mounting again made the slave PFS in sync with master.
It may not be possible in your case as yours seem to be / fs.

2016-08-24 12:53 GMT+09:00 Lanir <lanir at>:
> Hi,
> I think I must have setup the mirroring incorrectly because nothing is
> happening. I tried following the guide "how to implement hammer pseudo
> file system( pfs ) slave mirroring from pfs master" on the website but
> something appears to have gone wrong.
> I have two 7.3tb hammer filesystems spread over two physical disks each
> on the same system. I had problems creating the slave PFS so created it
> as a master, demoted it, then altered the shared-uuid to match before
> trying to mirror it. When I do a mirror-copy I get this result:
> # hammer mirror-copy /usr/stor/backups /usr/backup-stor/pfs/backups
> Mirror-read /usr/stor/backups succeeded
> #
> The data is obviously not being copied over:
> # df -h /usr/stor /usr/backup-stor
> Filesystem                       Size   Used  Avail Capacity  Mounted on
> stor1                            7.3T    44G   7.2T     1%    /usr/stor
> backup-stor1                     7.3T   1.0G   7.3T     0%
> /usr/backup-stor
> As far as I can tell they're setup correctly:
> # hammer pfs-status /usr/stor/backups /usr/backup-stor/backups/ | egrep
> '(shared-uuid|operating)'
>     shared-uuid=4138d697-3355-11e5-99b1-e13f494aab78
>     operating as a MASTER
>     shared-uuid=4138d697-3355-11e5-99b1-e13f494aab78
>     operating as a SLAVE
> Can someone help point me towards the problem? I feel like I may have
> missed something.
> Thank you!

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