PFS mirror problems

[Lanir]

I was able to reproduce it. This is actually my second attempt at this,
tried remaking the filesystem earlier. When I have the time to back
everything up I'll try remaking the slaves and their hammer filesystem.
Make take a week or so but I'll document it when I do.

Thanks!

Lanir



On 08/27/16 07:05, Tomohiro Kusumi wrote:
> I tried to reproduce it, but doesn't reproduce with below.
> A pfs in / gets copied to a pfs in /HAMMER.
>
> # cat -n ./pfsd2.sh
>      1  #!/usr/local/bin/bash
>      2
>      3  HAMMER_DEVICE=/dev/da1
>      4
>      5  cd
>      6  umount /HAMMER
>      7  newfs_hammer -L TEST ${HAMMER_DEVICE} > /dev/null
>      8  mount_hammer ${HAMMER_DEVICE} /HAMMER
>      9  cd /HAMMER
>     10
>     11  hammer pfs-master a
>     12  hammer pfs-downgrade a
>     13  hammer pfs-update a `hammer pfs-status /pfs/tmp | grep shared-uuid`
>     14
>     15  hammer mirror-copy /pfs/tmp a
>     16
>     17  du -sh /HAMMER/a/
>     18  cd
>     19  umount /HAMMER
>     20  mount_hammer ${HAMMER_DEVICE} /HAMMER
>     21  du -sh /HAMMER/a/
>
>
> Doing something like below may end up not copying a file, but not sure
> if this is technically what you're seeing.
> This happens in older versions (3.x) too.
>
> # cat -n ./pfsd1.sh
>      1  #!/usr/local/bin/bash
>      2
>      3  HAMMER_DEVICE=/dev/da1
>      4
>      5  cd
>      6  umount /HAMMER
>      7  newfs_hammer -L TEST ${HAMMER_DEVICE} > /dev/null
>      8  mount_hammer ${HAMMER_DEVICE} /HAMMER
>      9  cd /HAMMER
>     10
>     11  hammer pfs-master a
>     12  hammer pfs-slave b `hammer pfs-status a | grep shared-uuid`
>     13
>     14  dd if=/dev/urandom of=./a/xxx bs=1024 count=1
>     15  #sync; sync; sync; sync; sync
>     16  hammer mirror-copy a b
>     17
>     18  cd
>     19  umount /HAMMER
>     20  mount_hammer ${HAMMER_DEVICE} /HAMMER
>     21  ls /HAMMER/*
>
>
> 2016-08-25 19:35 GMT+09:00 Tomohiro Kusumi <kusumi.tomohiro at gmail.com>:
>> I'll see if I can reproduce it within a few days and try to fix it if
>> that's a bug,
>> since I'm currently trying to fix lots of PFS related bugs.
>>
>> 2016-08-25 5:31 GMT+09:00 Lanir <lanir at cisns.net>:
>>> I'm on 4.6-RELEASE.
>>>
>>> When I unmounted and remounted the base hammer filesystem it showed a
>>> matching size. But when I stop the mirror-stream and mount the
>>> former-slave PFS, I have no data to show for it. After a reboot the size
>>> is off again.
>>>
>>> I'm a little confused about what's actually going on with it at the
>>> moment. Data appears to be there but inaccessible. I think that bug is
>>> related to what I'm seeing.
>>>
>>>
>>>
>>>
>>> On 08/24/16 09:37, Tomohiro Kusumi wrote:
>>>>> This might be related to the bug I reported:
>>>>>
>>>>> http://bugs.dragonflybsd.org/issues/2915
>>>> Lanir,
>>>> Based on Tim's report on DragonFly 4.5, what's your uname -r ?
>>>>
>>>>
>>>>
>>>> 2016-08-24 22:23 GMT+09:00 Tomohiro Kusumi <kusumi.tomohiro at gmail.com>:
>>>>> BTW what I mean by unmounting is unmounting hammer, but not PFS (if
>>>>> you've null mounted them somewhere or your dfly installer has done
>>>>> it).
>>>>>
>>>>> 2016-08-24 22:14 GMT+09:00 Tomohiro Kusumi <kusumi.tomohiro at gmail.com>:
>>>>>> 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 cisns.net>:
>>>>>>> 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!
>>>>>>>
>>>>>>>
>>>