rsync - Sep 2004 - question about 2.6.3pre2's --link-by-hash behaviour

I had noticed the --link-by-hash patch a short while back & decided it was
time to experiment with it. Sadly, its behaviour is considerabely different from
what I expected - to the point that I find it unusable in its current form. I
had hoped to use it both for my rotating backups & for my (unofficial)
slackware mirror.

For the test itself, I did the following:
- created 3 directories in /tmp/: src/ dst/ hash/
- put a random small file in src/, then made 3 non-hardlinked copies which
differ by date, owner & group, last modified date.
- gained root, issued the following command:

[root@lithium ~]# /home/erik/pkg/pre/usr/bin/rsync -aPv --link-by-hash=/tmp/hash
/tmp/src/ /tmp/dst/

The result:

[erik@lithium ~]$ ls -l /tmp/src/
total 16
-rw-r--r--  1 erik   users   395 2004-09-14 17:07 orig
-rwxrwxrwx  1 erik   users   395 2004-09-14 17:07 orig+mode*
-rw-r--r--  1 nobody nogroup 395 2004-09-14 17:07 orig+owner.group
-rw-r--r--  1 erik   users   395 2004-09-22 04:25 orig+time

[erik@lithium ~]$ ls -l /tmp/dst/
total 16
-rw-r--r--  5 erik users 395 2004-09-14 17:07 orig
-rw-r--r--  5 erik users 395 2004-09-14 17:07 orig+mode
-rw-r--r--  5 erik users 395 2004-09-14 17:07 orig+owner.group
-rw-r--r--  5 erik users 395 2004-09-14 17:07 orig+time

(The 5th link being the hash file itself)

My question is simple enough. Are there plans to make --link-by-hash pay
attention to file externals?

Erik

-- 
Registered Linux User Number 140066
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=140066

"Failure is not an option. (It comes bundled with Windows.)"
"If it ain't broke, overclock it."

On Wed 22 Sep 2004, Erik Jan Tromp wrote:
> I had noticed the --link-by-hash patch a short while back & decided it
was time to experiment with it. Sadly, its behaviour is considerabely different
from what I expected - to the point that I find it unusable in its current form.
I had hoped to use it both for my rotating backups & for my (unofficial)
slackware mirror.
[ snip demo ]

Hmmm... For a slackware mirror I expect that it would be fine.

I tried downloading the patch from the web cvs, but I got this:

    Error: Unexpected output from cvs co: cvs [checkout aborted]:
    Absolute module reference invalid:
    `/rsync/patches/link-by-hash.diff'

    Check whether the directory /cvsroot/CVSROOT exists and the script
    has write-access to the CVSROOT/history file if it exists.  The
    script needs to place lock files in the directory the file is in as
    well. 


Paul Slootman

On Wed, Sep 22, 2004 at 04:54:32AM -0400, Erik Jan Tromp
wrote:
> Are there plans to make --link-by-hash pay attention to file externals?
The issue has come up before:

http://lists.samba.org/archive/rsync/2004-February/008630.html

I don't know of any plans for changing the --link-by-hash patch, but if
someone is interested in working on it, I can integrate changes into it.

One simple change would be to prime the computed hash using some
external data (e.g. uid, gid, and/or mode), but it sounds like at least
the original creator would like this to be optional.

..wayne..