On Tue, Oct 28, 2014 at 09:36:09 +0100, Stefan G. Weichinger wrote: > > If I use amgtar as amanda application, how does it handle hard links? > > A customer tells me he has some pictures in a website and does hardlinks > to save space. > > When he restores from amanda he gets several copies of one and the same > picture and no hard links created? > > Is that expected behavior? How to handle this?
GNU tar as called normally by Amanda will automatically detect files with multiple hard links and will add the second-and-later references to the archive as links to the first name processed. (See http://www.gnu.org/software/tar/manual/html_node/hard-links.html for further details.) However, this only works if the various references to that file are included in the same DLE (and thus are backed up together in a single tar run). If that requirement is met in your customer's case, there's probably something more subtle going on... in which case it would be helpful to know the OS/distribution/Amanda/tar versions involved, a bit more about how the website directories are set up and the DLE that backs them up, and the exact sequence of operations he used when trying to do the restore.... > I read about "-h" and "-H" for gnu-tar, but that influences the *backup* > not the restore. (Note that "-h" is an alias for "--dereference" and specifies behavor related to symbolic links, while "-H" is unrelated [it's an alias for --format]. There is a "--hard-dereference" option [with no single-letter alias], but in this use case you specifically don't want to dereference the hard links so you wouldn't want to use that option.) Nathan ---------------------------------------------------------------------------- Nathan Stratton Treadway - [email protected] - Mid-Atlantic region Ray Ontko & Co. - Software consulting services - http://www.ontko.com/ GPG Key: http://www.ontko.com/~nathanst/gpg_key.txt ID: 1023D/ECFB6239 Key fingerprint = 6AD8 485E 20B9 5C71 231C 0C32 15F3 ADCD ECFB 6239
