Feature request: allow --link-dest dir to be linked to even if file exists in target.
This statement from the man page is adhered to too strongly IMHO: "This option works best when copying into an empty destination hierarchy, as rsync treats existing files as definitive (so it never looks in the link-dest dirs when a destination file already exists)". I was suprised by this behaviour as generally the scheme is to be efficient/save space with rsync. When the file is out of date but exists in the --l-d target, it would be great if it could be removed and linked. If an option was supplied to request this behaviour, I'd actually throw some money at making it happen. (And a further option to retain a copy if inode permissions/ownership would otherwise be changed.) Reasoning: I backup many servers with --link-dest that have filesystems of 10+M files on them. I do not delete old backups - which take 60min per tree or more just so rsync can recreate them all in an empty target dir when <1% of files change per day (takes 3-5 hrs per backup!). Instead, I cycle them in with mv $olddate $today then rsync --del --link-dest over them - takes 30-60 min depending. (Yes, some malleability of permissions risk there, mostly interested in contents tho). Problem is, if a file exists AT ALL, even out of date, a new copy is put overtop of it per the above man page decree. Thus much more disk space is used. Running this scheme with moving old backups to be written overtop of accumulates many copies of the exact same file over time. Running pax -rpl over the copies before rsyncing to them works (and saves much space!), but takes a very long time as it traverses and compares 2 large backup trees thrashing the same device (in the order of 3-5x the rsync's time, 3-5 hrs for pax - hardlink(1) is far worse, I suspect a some non-linear algorithm therein - it ran 3-5x slower than pax again). I have detailed an example of this scenario at http://unix.stackexchange.com/questions/193308/rsyncs-link-dest-option-does-not-link-identical-files-if-an-old-file-exists which also indicates --delete-before and --whole-file do not help at all. /kc -- Ken Chase - k...@heavycomputing.ca skype:kenchase23 +1 416 897 6284 Toronto Canada Heavy Computing - Clued bandwidth, colocation and managed linux VPS @151 Front St. W. -- Please use reply-all for most replies to avoid omitting the mailing list. To unsubscribe or change options: https://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html