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Knowing where to start on this is a bit of a miffing point.

First: upgrade your shit. 2.4 kernel systems? Are you running Redhat 6? You know, from the turn of the millennia.

Second: upgrade your shit. Really,

Third: if your kernels are that old and you're using these machines for file storage/backup, chances are the hardware needs to be replaced before you even consider considering messing with them. Seriously: this stuff is ancient. Even Debian hasn't had a 2.4 kernel in 5+ years, I think.

Third: you can do what you're trying to do with rsync 'snapshots'. It works very well, failing filesystem level support. If you're sharing data over samba, this makes it easy: just put a '.snapshot' dir for these 'temporary' backups in their $HOME and hide dotfiles. Then make sure rsync ignores .snapshot. (Of course, there are other ways to do this.)

rsync snapshots (and here).

There are other sources of information out ther on rsync snapshots. There's also rsnapshot.

Chances are you'll have to upgrade before this stuff even works for you, though.

Hash collisions are FUD spread around by IBM, who happened to buy the only deduplication company in existence that doesn't rely upon mathematics to compare signatures. Most deduplication uses multiple, independent algorithms to verify uniqueness. There has never been a confirmed instance of a hash collision on a deduplication system that uses independant algorithms. In the meantime, there are lots of other ways to lose data on a hard drive, not the least of which is the combination of a weak filesystem coupled with an OS prone to crashing (but I'm not naming names.)

I don't always agree with Curis Preston, but I think the hash collision FUD has effectively put to rest here. http://www.backupcentral.com/index2.php?option=com_content&do_pdf=1&id=145

tape only has a recommended shelf storage life of 6 months

I don't know what kind of tape you're talking about, or whose recommendation, or if you're just trolling, but DLT has a shelf life of 30 years, according to the manufacturer, as well as other folks.

Of course, all this can easily be found by searching google. The phrase "30 years" pops out in the excerpt below just about every link.

I've worked with tape long enough to know that "6 months" is way too short a figure. Of course, I've never restored from a 30-year old DLT IV tape, since they aren't that old, but I've recently done a restore from a 9-track tape from 1979. I've routinely restored from CompacTape III cartridges which are at least six *years* old. In any case, six months is way too short for a recommended shelf life.

Sure, you've got to take good care of tape, if you want it to last, but it's a heck of a lot more durable than hard drives. I just drove a bunch of DLT and 4mm tapes 3000 miles across the country this summer in the hot, humid, and shaky back of a U-Haul truck, alongside a bunch of (small, old and mostly worthless) hard drives. When I got there, all of the tapes worked, but (unsurprisingly) about 40% of the hard drives were dead.

I know that my company hires people to do linux, as we are onsite support for RedHat. Hence, we give tech talks concerning all sorts of different stuff. Recently, Curtis Preston gave a talk in Boston concerning Backup Recovery practices. I know with all the linux people within the company, we could dig someone out to talk about the place of open source systems in the corporate environment.

--
Gonzo Granzeau

Disclaimer: I do like some veritas software including Volume Manager and VxFS.

Veritas NetBackup is *crap*. It's an old product made by a company called OpenView in the 80's which has never been properly integrated with modern Unix. The interface is a nightmare, it installs 3 tons of shit all over your filesystem in places you don't want it. It installs 3 dozen new services into inetd (a service for each tape drive ro something like that!!!). The GUI is woefully inconsistent and counter intuitive. Overall, I find it very inflexible and difficult to automate. On top of this, the documentation is pathetic. Oh, and don't go on the training course, you just get to sit in front of a power point presentation for three days. And guess what the course documentation is? Copies of the powerpoint slides. *bangs head against desk*.

I have looked at this several times over the past year and each time, I have gone back to plain old gnutar.

Also, I note that they are violating the GPL by including an old version of GNU Tar (1.09, so old it doesn't use --help, but +help instead) with modifications, but no source code available.

It's a shame, but I find this symptomatic of practically every piece of commercial Unix software that I have seen. They treat the system as something to be pushed away and ignored, rather than integrated with. So, I invariable end up going with the open-source alternative if at all possible. Ah well, their loss of sales.

To be fair, I think that the software would work a lot better if I had a tape library available to me instead of the poxy DLT4700 stacker that I have now. You may be able to get a better (and less biased) opinion than mine over at backupcentral.com.