rsync - Nov 2019 - hardlinking missing files from src to a dest: didn't work way I thought it would.

Am 14.11.19 um 10:54 schrieb Paul Slootman via rsync:
> You need to specify the source directory as the link-dest directory.
Hi, I tried it also because it's an old question which has never worked
for me. Instead it creates copies and not hard links:


pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 0
pierre at in94:~/tmp$ rsync -av --link-dest=a a/ b/
sending incremental file list
--link-dest arg does not exist: a
./
1
2

sent 194 bytes  received 95 bytes  578.00 bytes/sec
total size is 10  speedup is 0.03
pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 8
257312 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
257313 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2


Any idea why it's not working?


Using cp -l is working well:

pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 0
pierre at in94:~/tmp$ cp -l a/* b/.
pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 2 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 2 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 8
257315 -rw-r--r-- 2 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 2 pierre pierre 6 Nov 14 10:53 2

Cheers,
Pierre

On Thu 14 Nov 2019, Pierre Bernhardt via rsync wrote:
> Am 14.11.19 um 10:54 schrieb Paul Slootman via rsync:
> > You need to specify the source directory as the link-dest directory.
> 
> Hi, I tried it also because it's an old question which has never worked
> for me. Instead it creates copies and not hard links:
> 
> 
> pierre at in94:~/tmp$ ls -li a b
> a:
> insgesamt 8
> 257315 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
> 257316 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2
> 
> b:
> insgesamt 0
> pierre at in94:~/tmp$ rsync -av --link-dest=a a/ b/
> sending incremental file list
> --link-dest arg does not exist: a
There's your clue.
>From the manpage:
    If DIR is a relative path, it is relative to the destination
    directory.

So it's looking for b/a as the link-dest directory.

Use a full pathname for --link-dest to remove all uncertainty.
E.g.:

    rsync -av --link-dest=$(pwd)/a a/ b/

In this case, as the destination is also in same current directory, you
could use:

    rsync -av --link-dest=../a a/ b/


Paul

Am 14.11.19 um 15:02 schrieb Paul Slootman via rsync:
> On Thu 14 Nov 2019, Pierre Bernhardt via rsync wrote:
> So it's looking for b/a as the link-dest directory.
> 
> Use a full pathname for --link-dest to remove all uncertainty.
> E.g.:
> 
>     rsync -av --link-dest=$(pwd)/a a/ b/
> 
> In this case, as the destination is also in same current directory, you
> could use:
> 
>     rsync -av --link-dest=../a a/ b/
Working:

pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 1 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 1 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 0
pierre at in94:~/tmp$ rsync -av --link-dest=$(pwd)/a a/ b/
sending incremental file list
./

sent 98 bytes  received 19 bytes  234.00 bytes/sec
total size is 10  speedup is 0.09
pierre at in94:~/tmp$ ls -li a b
a:
insgesamt 8
257315 -rw-r--r-- 2 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 2 pierre pierre 6 Nov 14 10:53 2

b:
insgesamt 8
257315 -rw-r--r-- 2 pierre pierre 4 Nov 14 10:53 1
257316 -rw-r--r-- 2 pierre pierre 6 Nov 14 10:53 2


But it's really complex to understand. Why it's not possble to simply
create hard links if source and target is on the same filesystem and
use a simple option instead of the sourc-link-complex-option.

Is this for linke backup reason if the source dir is different
from the link-dest dir because of different hosts like

rsync -av --dest-link=../a a/ backuphost:b/

where on backuphost a is an older copy and b is the new
target?

Cheers,