Good rule of thumb:
If it's spinning, it's not a backup.

I've got irreplaceable stuff (photos mainly) on DVD off-site (at work) and my /home, /etc and /var are backed up incrementally onto a USB drive using this method (modified to taste, obviously):
http://www.mikerubel.org/computers/r...s/#Incremental

Also, quick plug for my CD/DVD burning script should anyone want a CLI CD/DVD burner:
http://sourceforge.net/projects/multiburn/

Dave

nx5000, it's a good way to support a company trying to invest in Linux. I'd buy a copy of the latest Nero for Linux if I had the cash. Their products work, and if Nero succeeds, it shows other companies they have a chance too. First step is support on Free software, next is actually writing some ; )

Oh, and Nero's currently the only app that can burn HD-DVDs and possibly Blu-rays.

I have never seen any recordable hd-dvds, but I have come across BD-R and BD-REs, quite expensive. One disc, around $25 or so, for 30GB.

The name on the cover really doesn't mean that much. Instead you should worry about who it's actually made by. Where it's made tells you a lot about that. If it's made in Japan, it's probably made by Maxell or Taiyo Yuden. If it's made in Singapore, probably Mitsubishi Chemicals(also good). If it's made in Taiwan, it's likely Ritek or CMC magnetics. If it's made in India, it's by Moser Baer AFAIK.

Yes I agree. I didn't check the linux version nor its license but I guess (and understand due to their business model) that it's still proprietary. So... In a way I prefer if they stay out rather than come with proprietary software in the opensource world.
It's just two different worlds and I really don't install anything proprietary on my GNU/Linux, I would rather go back to windows.
The only optical disks I use are Cds

edit:
Maybe I haven't been in enough companies yet but I've never seen a professionnal backuping on optical disks. The tapes are quite efficient, cheap and quick but needs special readers for the home user..

Tape archives will lose their polarization, and thus their data over time. It happened in a lab I used to work in.

Also, anything full of moving parts (read: all hard drives) must fail eventually, regardless of brand etc. Some just go sooner than others...

Right. There's not really a foolproof backup method. Just the best method for your situation. Mechanical devices fail, optical devices degrade over time, and singularly don't hold a lot of data, magnetic media (tapes) also degrade, and can be very expensive when large capacity is a question.

At home my primary backup of archival data is to CDs and DVDs (non-rewritable), and backup of active data is to 2 synced data stores on 2 hard drives on 2 separate machines.

Spin off of original post, and rhetorical question: As far as my backed up archive data, I've got images and music. What is the guarantee that the JPG and MP3/OGG formats would be viable in 30-50 years? Each time a file is converted to a different format, some of its quality is lost. Of course, I probably won't care about my 80's hair band music when I'm 70 ... or will I?

Well, a slight good came out of this. A friend of mine had a majority of my music, ~70GB, plus I was lucky enough that he had copies of my vaction pictures, so I kinda got lucky. I am planning to burn all that data on DVDs as soon as I get them, but there is so much, I may have to invest in double layered discs. I have always had pretty good luck with the Verbatim brand, all the way back to CD-R, I never use RWs, a waste of time, and not reliable as WORMs. Even when I burn CD/DVDs, I always use only one session, and close it out/finalize it. I never do packet writing, just DAO all the way.

An external drive isn't an different than an internal so you shouldn't keep your only copy there, it should be a copy of the data on your internal drive.
Also you shouldn't rely on only one type of media, always use more than one type for backups, I use an external drive and cd-r/dvd-r's.
Third, never buy a "USB hdd" always buy the drive and usb enclosure seperate so you know what your getting. The pre-assembled ones always come with crap drives.

True that! Bad, Maxtor. Bad! Sorry to all of you with Maxtor drives, but ... blech!

My theory is to backup in triplicate. I send all of my pictures to at least two other family members on CD, I also keep a set for me and I also save data onto a large Hard Drive (Seagate) that I do not ever use except to make these one a month archives (Minimizes spin ups and downs), and because I am paranoid I also make a full annual backup including the OS and everything.

How far can we go to make sure that we have a trustworthy backup of the precious data of ours?
Well... let me put it this way:

"Working media" is the media storage where you process or in other ways use the data in daily basis.
"Backup media" is the media storage where you keep a copy of your data, safely away from any threats, ONLY accessed when updating or restoring the data.

Too many times I've stumbled over people who believes that storing their backups in a separate partition "D:\" is enough to keep them safe from harm, some even believes that a separate folder on the desktop is enough.

Pickup your backup media in your hand, take a good look at it and then answer those questions:

* Can it be physically disconnected/ejected? (a backup media shall ONLY be connected/inserted when accessed for update/restore)
* Can it be used with another computer? (a backup media shall be usable with the new computer in case that the old computer goes unusable)
* Can it be stored in a case/cover? (a backup media's lifetime is only as good as it's environment allows it to be)

If you answer "no" on anyone of those questions about your backup media, that means the backup media in mind isn't good enough for a proper backup.
External harddisks are useful if they fulfill the three conditions above.

Having the backup media (e.g. a hardisk) always connected and online (spinning) is one of the worse things you can do, since this WILL make it's lifetime significant shorter, even risking a mechanic failure.
All storage media WILL fail one way or another, it's just a matter of time.

List of potentional bad backup media:
* Memory cards (static electricity, even very small unnoticeable amounts of static electricity can render a memory card/chip totally useless. I can confirm)
* CD / DVD (re)writable (Very sensitive to their environment where heat, sunlight etc. and most of them are badly protected from scratches on the label-side. I can confirm)
* Floppy/Diskette (Is the anyone still using these? Anyhow, most of them got an extremly high risk for bad sectors. I can confirm)

I remember a scenario with floppies once upon a time:
I was about to restore a backup stored on a few (100) 3.5" floppies when I suddenly got an error message about some read error and then a message about aborting, retrying or failing the attempt, this at disk number 71. Tough luck!
Replacefloppy number 71 with the one from the second backup set (yes, I always had two sets of the same backup at that time).
Beginning to restore the data again from floppy 1 (the backup program couldn't continue after that error no matter what I tried.)
On the way to a restored system it shows up that disk nuber 95 also got some bad sectors ...

. . . *sigh* . . .

replacing ... starting over AGAIN.

Disk number 99 also broken, on both sets! *giving up after a few hours* . . . I litterally ... hate ... floppy disks!

SysGhost: 200 floppies?!? Good god... No wonder you hate floppy discs.

I backup everything onto WORM DVD. Approximately monthly, or whenever I'm doing something that might nuke my documents if I get it wrong.
I'm planning to get a fire resistant safe to store my backups in, but for now they're just stacked in a spindle case.

Currently, all my documents (including music) can fit onto a single layer DVD, so I think my self lucky. I don't have a lot of large documents, just lots of little files.

If you really want to backup to external hard drives, you need to have two external hard drives, and copy your data to both of them. Further, these are your backups, not your archive - these presume that you will also have your archive copies someplace else.

My commercial software resides on my workstation. A backup copy of my commercial software resides on an encrypted partition on my laptop (encrypted because the laptop travels with me and could get stolen). The other backup of my software resides on a pen drive which I usually keep in my car. After a major release, the release code goes on a dvd which goes to the bank safety deposit box, and every now and then I update that dvd.

The point? I *should* be covered no matter what happens; fire, theft, accidental data loss - none of those can separate me from at least one recent copy of my source code.

As for multimedia, pictures, etc., I presently back them up to two different external drives. Really what I do is scroll all that stuff off to one drive then synch that drive with the other one on a weekly basis. Not as proof against loss, but proof against the single point of failure loss that a failed HD represents.

What about rotating backups? One backup is never a smart choice when it comes to irreplaceable memories.

BTW, I had a hard drive fail that had our first family vacation in 15 years archived on it. And, about two years of photos, so I understand your pain.

[Edit]
I like the idea of backing up to several kinds of media: USB key, CD-R, DVD-RW, unplugged hard drive. I'd be wary of magnetic media though...one good swipe with the right magnet and your data is wiped clean.
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