Les Mikesell <lesmikesell at gmail.com> wrote: > My favorite for online disk backups: > http://backuppc.sourceforge.net/ > It uses compression and linking of duplicate files to allow > holding much more data than you'd expect so you can keep > some history around. Yes, I use it myself. > The free version is to image-copy the backuppc archive > filesystem to an external drive. It's cheaper than a fast > tape drive and you can plug the external disk into a laptop > anywhere for immediate remote restores without needing > another tape drive. How many times do I have to say it, I _never_ backup directly to tape. I _always_ backup to disk. ;-> I then do _not_ commit every backup to tape, only a subset. Anyone who backs up everything -- let alone everything directly to tape -- is living in the '80s. There is nothing more chronically stupid than direct backup to tape -- especially over a network. I don't know how many times I go into companies and they are still trying to do end-node to tape-server backups in an 8 hour window and just can't do it. I always just hit my head and say, "why don't you sync your filesystem changes to a centralized server, and then backup from that system locally to the tape -- which you can do in the middle of the day?!" It's like an epiphany for them -- so obvious they missed it. You should at least buffer to disk first, if not just store backups whole on disk. Then and only then should any long-term backups, retention or off-site considerations be put to tape -- locally on the same system. But not everything has to go to tape -- in fact, a _minority_, only those things that are going off-site or need to be stored longer than a few months. At the same time, don't trust backups for months on a fixed disk. > The downside has been firewire support on Linux the way I'm > trying to do it, which is to periodically sync a RAID1 mirror > and break it for offsite storage. I'd rather not backup in a filesystem format. I'd rather backup to a streaming archive format which is far more recoverable when there are errors. That way errors are localized and don't affect the rest of the backup. Filesystems rely on meta-data to recover data -- streaming archive formats do not. As far as off-line storage, I do not trust commodity fixed disk more than 3 months on the shelf (if even that long). They are not designed to be stored that long and inactive after periodic activity. The vendors have come up with removable rigid disk (RRD) to address the longevity issues, but then RRD loses the performance or cost of fixed disk. > I suppose I could unmount the internal disk and use dd to > copy for the same effect. Why not a streaming backup format like afio or ustar? Far more recoverable and errors are localized than with a traditional filesystem. -- Bryan J. Smith | Sent from Yahoo Mail mailto:b.j.smith at ieee.org | (please excuse any http://thebs413.blogspot.com/ | missing headers)