On Mittwoch 22 April 2009, Joerg Schilling wrote: > Volker Armin Hemmann <volkerar...@googlemail.com> wrote: > > On Mittwoch 22 April 2009, Joerg Schilling wrote: > > > Thomas Chef <thomas.c...@gmail.com> wrote: > > > > Now that my gentoo system is up and running the applications that I > > > > want to use, how do I make a reliable backup ? > > > > > > > > Can I follow the guide on: > > > > http://en.gentoo-wiki.com/wiki/Backup_to_DVD > > > > > > > > Is that a proven/working method ? > > > > > > Be very careful as GNU tar is buggy and does not always like to read > > > continuation volumes from multi volume archives. This is extremely > > > nasty as you will realize the problem once it is too late. > > > > oh really? it works very well with my tapelib. And yes, restore works. > > There is a 1-5% chance that GNU tar does fail this way, did you try to > restore enough GNU tar multi-volume archives? Did you restore more than 100 > multi-volume archives?
No, just a couple of douzend so far. My lib takes 8 cardridges. So far no problems. I did maybe four or five complete restores so far. Before that I had a single dlt drive and played disc jokey - no problems there too. So I am well below the 100 multi-volume archives, but well above the 30 mark. > > GNU tar uses a method for multi-volume archives that cannot support all > possible cases. Star uses a mwthod that is granted to always work reliably. > > > > GNU tar also does not support to archive all meta data from Linux. > > > > which is only relevant if you use acls, isn't it? > > ACLs, xattrs and others. > okay. Then tar is still good enough for me. See, it is a good thing that you wrote star (and cdrecord and other things). Your code is much appreciated - but I am very reluctant to use a piece of software when another one I am currently using is 'good enough' for me. Since I don't use acls or xattrs the lack of support in gnu tar does not hurt me. I also had a hard time to figure out the optimal command line to use my tapelib - I don't want to do that again with star if I don't have to. > > > I recommend to use star. Star implementes reliable multi volume support > > > and archives all meta data that is available on Linux. Only a reliable > > > multi volume support inside the archiver allows you to read back > > > archives starting past volume#1. > > > > can star decompress files? > > Are you kidding? nope. http://bulk.fefe.de/lk2006/ For some reason, my tar hung on Solaris. I have no idea why. truss showed that it wasn't in a syscall at that time. So I used star instead. Turns out that star can't do "star xzf -", it will say "Can only compress files." ROTFL! OK, so I used "|gzip -dc|star xf -" instead. What the hell.
