At 2:30 PM +0200 8/9/07, M. Fioretti wrote: ... >create something that is completely readable with any operating system >(including hidden files, links, long file names...): what if I need to >recover files from there from a friend's Mac or Windows laptop? This is >a filesystem question, so how would I format/ (re) create it? I like to do uncompressed tar direct to DVD. The machine reading the DVD needs tar, but it doesn't need any compatible filesystem, and all the file attributes are in the archive. Tar will be available into the future. Of course, extracted files might lose some of their meta-data if the destination filesystem won't handle it. I recommend against compression only because a single-bit error will ruin the rest of the data. For large amounts of data, use tar's multi-volume feature (which, AIUI, requires using a temp file and writing the DVD from that -- I don't know a way to get growisofs to "change disks"), and also possibly tar's incremental feature. Personally, in addtion to occasional backups of my local machine, I'm backing up a server every few hours to another "warm backup" server, and monthly to a local disk volume, and from that making a DVD monthly. The server's data fits easily on a DVD, so I haven't used tar's multi-volume feature for the server, and I haven't use tar's incremental feature at all. >check periodically, as quickly as possible, that everything is still >intact, that is that no single files or links etc... have been damaged. >Ideally, I'd make this last thing an option of the script itself, that is >"check the drive first, and if everything is fine proceed with the >new backup operation" How do you define "damaged? I would think that files and links are allowed to change between backups. If you just do the backup, it won't hurt any existing backups. ... >Now a couple of OT question, answers to these are much better sent off list. > >1) What about reliability of hard disk versus DVD based backups? > Links to relevant reading are welcome. ... Hard disks and optical media are different, and so is the data format, so having both kinds of backup will be more robust than either alone. Do an rsync to the other hard disk, and back that up to DVD. As has been mentioned, the hard disk could be made bootable, but I prefer the reinstall and restore approach. -- ____________________________________________________________________ TonyN.:' <mailto:tonynelson@xxxxxxxxxxxxxxxxx> ' <http://www.georgeanelson.com/>
