Unison and Hammer History

[peeter (must)]

On Tue, Jan 22, 2013 at 11:55 AM, peeter (must) <karu.pruun at gmail.com> wrote:
> On Tue, Jan 22, 2013 at 2:47 AM, Predrag Punosevac
> <punosevac72 at gmail.com> wrote:
>> "peeter (must)" <karu.pruun at gmail.com> wrote:
>>
>>> On Sat, Jan 19, 2013 at 5:11 AM, Predrag Punosevac
>>> <punosevac72 at gmail.com> wrote:
>>> > Greetings all!
>>> >
>>> > I am completely new to DragonFly BSD although not to BSDs in general and
>>> > this is my first post the list so bear with me just a little bit.
>>> >
>>> > I am running DragonFly (HAMMER file system of course) on Dell PowerEdge
>>> > R210 II Ultra-compact Rack Server. Everything works like a charm (let me
>>> > know if you need a dmesg).  This machine is a new file server for my
>>> > cloud computing lab. It essentially runs only one service SSH and has
>>> > only two pieces of additional software installed CVS and Unison. It is
>>> > supposed to act as a CVS server and a remote storage.
>>> >
>>> > I am in the process of playing with HAMMER and writing wiki for my
>>> > users.
>>> >
>>> > I am a bit confused by the interplay of hammer history and Unison so I
>>> > was wondering if some kind soul could explain me what is going on?
>>> > Namely when I sync files with Unison from my home desktop the hammer
>>> > history shows as a date of the file creation the time of the last
>>> > synchronization. When I change files locally I can clearly see the
>>> > history and I can pull old versions from the journal. Why can't I see
>>> > file changes which are propagated with Unison from my desktop in the
>>> > hammer history?
>>>
>>>
>>> I guess it depends on whether Unison has changed the given file on the
>>> server since last pruning, which I think happens every night at about
>>> 3am?
>>>
>>> As a simple test, you can do on the server
>>>
>>> > touch someFile
>>> > echo "1" >> someFile
>>> // wait for a minute
>>> > echo "2" >> someFile
>>> > hammer history someFile
>>>
>>> Does it show some history?
>>>
>>> Peeter
>>>
>>> --
>>
>> Yes it does!
>>
>> $ uname -a
>> DragonFly hammer.ccl.aug.edu 3.2-RELEASE DragonFly v3.2.2-RELEASE #0:
>> Sun Dec 16 13:26:10 PST 2012 root at pkgbox64.dragonflybsd.org:/usr/obj/build/home/justin/src/sys/X86_64_GENERIC x86_64
>> $ touch someFile
>> $ echo "1" >> someFile
>> $ hammer history someFile
>> someFile        0000000102afd692 dirty {
>>     0000000102c79fc0 21-Jan-2013 21:16:17
>> }
>> $ echo "2" >> someFile
>> $ hammer history someFile
>> someFile        0000000102afd692 dirty {
>>     0000000102c79fc0 21-Jan-2013 21:16:17
>>     0000000102c7a000 21-Jan-2013 21:16:48
>> }
>>
>> That is why I am so confused. When I change files on the server history
>> is ok. But when I change files on my own desktop and synchronize with
>> Unison history shows only the time of the last synchronization not
>> previous versions.
>
>
> OK I see the same happening with rsync. Seems to me that rsync (and
> possibly unison as well) delete the old file and then create a new
> file. Each time a file is changed on the desktop, when you do rsync,
> it looks as a newly created file on the server with no history and a
> single line for transaction and time stamp; and the time stamp is the
> moment when rsync was done.
>
> Peeter
>
> --

Also note that this does not happen with scp---apparently it
overwrites a given file, so you see full hammer history.

Peeter

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