On Tuesday 17 November 2015 03:14:50 Thomas Schmitt wrote: > Hi, > > Christoph Anton Mitterer wrote: > > I'm looking for a backup solution with quite some specific needs,... > > My scdbackup with xorriso as backend might nearly do what > you want: > http://scdbackup.sourceforge.net/main_eng.html > > It initially demands some configuration effort > http://scdbackup.sourceforge.net/examples.html > http://scdbackup.sourceforge.net/README > > xorriso is available as Debian package, or as source tarball > https://www.gnu.org/software/xorriso/xorriso-1.4.0.tar.gz > > > - hard links must be retained > > - it must be possible to backup to split media (e.g. mutliple CDs) > > This is not easy to achieve. > Consider one hardlink sibling in one fileystem and the other > in the next filesystem. > > > - file times, owners (ideally as IDs and names), permissions, > > XATTRS, ACLs must all be retained > > scdbackup records them in scripts with setfattr and setfacl, > which it stores in data files in the backup. > xorriso records them too, but restoring those will need xorriso, > because Linux does not interpret AAIP (which is not astounding > because it is a libisofs extension to ISO 9660). > > ISO 9660 has the advantage of being readable nearly everywhere > as long as you restrict yourself to single-session and data > files smaller than 4 GiB. (BSD and Solaris ended development of > their ISO 9660 readers long ago. Meanwhile one can smell their > fermentation state.) > > > - I want always *full* files to be backuped > > - a single file shouldn't be split over multiple backup media > > (unless this isn't possible otherweise, because all targets are > > smaller than the file size) > > Putting together the pieces of large files is of course a pain > at restore time. > > > - ideally the program would offer two modes: > > - either trying to keep "neighbouring" files (i.e. those that are > > close to each other in the directory hierarchy) closely on the > > split target mediums > > You mean those with neighboring names, i assume. > (More or less the same as alphabetic ordering by name.) > > > - or trying to be as space efficient as possible (i.e. place files > > so that space is used most efficiently > > After a few years of cramming files, i switched to alphabetic. > > > - catalogues should be made, of both, all files and the files on a > > certain medium, also as a help in the disaster case > > Not to forget checksums. > In most dangerous storage environments one should consider to > make several identical copies of the media and have means to > recognize good blocks. > > > - as I've said, incremental backups should be possible,... but that > > should also work when I move files around > > So timestamps are not enough. > scdbackup has two ways of incremental backups: > - If inode numbers are persistent and ( devide numbers are persistent > or mount points always lead to the same filesystems), then it is > possible to decide by the outcome of stat(2). > - Much slower is decision on base of MD5 of file content. > > > Well I guess it wouldn't be too difficult to script most of this, > > scdbackup needed about seven years of try-and-error. > It can be done faster if you have a clear plan. > Beware of being sucked into neighboring topics like DVD burning > or backup-grade ISO 9660 production. > > > Have a nice day :) > > Thomas
I have been using amanda (Advanced Maryland Automatic Network Disk Archiver) since 1998 or 99. Setup here to use files on a BIG HD that are its "tape library", I have found such a setup to be both much faster when it comes to recovery, AND considerably more dependable than any tape format I can afford. Amanda has a different basic format, mixing backup levels in an attempt to use about the same amount of media per run. A typical run over the 4 machines live on my home network will run to about 40Gb, which it does in about 3.5 hours in the middle of the night. I do a 4 day cycle so I get a level0 full backup of every disklist entry at some point in those 4 days, mixed with incremental, only whats changed, in between times. And I can reach back as far as 30 days before that part of the disk is reused. So if I find something valuable has been erased, I have 30 days to discover it and recover it. There are tools which can make offsite, forever storage for amanda users. But I'm not recording business transactions I might have to recover for the Infernal Revenoo Service, I'm just a retired hobbiest making a stick or two of furniture when the mood strikes me. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene>
