On 02/11/2015 11:13 AM, Les Mikesell wrote: > On Wed, Feb 11, 2015 at 11:02 AM, Francis Gerund <ranrund at gmail.com> wrote: >> Hello. >> >> After some reading, including the rsync man page, I am still not clear on >> this: >> When using rsync to backup and restore, when should and when should one >> *not* >> include hard links (by using the -H option switch)? >> >> A simple example case would be backups for one or just a few light-duty >> local workstations. Is there a simple, clear rule about that, or is it too >> complicated for that? > > Use it unless the resulting backup run is too slow to be practical - > which will only be when there are vast numbers of hardlinks in the > filesystem which is pretty rare (backuppc's archive, for example). > That is, if you don't know whether or not you need it you are better > off retaining as much of the original filesystem attributes as > possible in your backups. But, keep in mind that it can only > reproduce the hardlinks that exist in the portion of the filesystem > that is covered in one run. If you do multiple runs covering > different subdirectories, it can't duplicate hardlinks outside of each > run. /var/lib/yum/yumdb and, to a lesser extent, /usr/share/zoneinfo are two places that use hard links a lot. If you _don't_ use "-H" you make multiple, independent copies of each file and have no way to restore the original hard link structure. If all you care about is not losing data, then it's just a space issue. If the ability to restore the original hard link relationships is important, then using "-H" is a must, no matter the performance penalty. -- Bob Nichols "NOSPAM" is really part of my email address. Do NOT delete it.