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What Software Do You Use for Unix Backups?
jregel asks: "Linus has stated that
dump should not be considered a reliable backup program, and both tar and cpio have their limitations. So what are Slashdot readers doing for backing up Linux servers and workstations? (you do backup, right?)" Given this bit of news, have you used anything other than the standard Unix staple to back up your Linux boxes? If you were forced off of tar, cpio and dump, what would you use as a replacement?
Amanda comes up a lot. They can't span tapes.
Veritas also comes up a lot. Aside from cost, did you know Veritas can't back up single files larger than 2GB in size on Linux clients?
On paper, BRU looks pretty darned good. I haven't yet put that theory into practice.
Seems to me that Linus (or another kernel hacker) should fix the ext2 race condition reported in that thread, rather than blithely dismiss the problem with, "dump was a stupid program in the first place."
If you overwrite the previous day's backup, what happens if the server crashes and loses all its data while the backup is in progress? It seems to me that you'd lose up to a week's worth of data if you switch tapes once a week, unless you actually append data to the end of the tape instead of overwriting it. But, as mentioned in the link you posted, appending data to the end of the tape isn't all so great either, plus you increase the chances of running out of tape, in which case you have to switch tapes anyway.
Not a criticism of your method (in fact, I use this), just a rant that the Linux MM system NEEDS TO BE FIXED. I'm sick of watching as some trivial process that will only read or write once gets the whole filesystem cached for it while programs I'm using interactively get swapped to disk. Video recording and playing programs (mplayer, ogle) have the same problem.
Let's hope 2.6 is better than 2.4. Can any kernel hackers comment on this? In 2.5 will tar cvjf /home /mnt/backup/home.tar.bz2 bring my system to its knees?
-- Bob
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
...major OS that doesn't have some kind of filesystem-snapshot support.
And this, more than any marketspeak CTO buzzwords, is what prevents Linux's entry into really mainstream server usage. Every sysadmin senior enough to make the decision of "do we use Linux for " knows that backing up a live filesystem is simply stupid. Right now -- and for the foreseeable future, since nobody seems to be working on it -- you have to unmount a filesystem and then use a program that speaks raw devices. And there went your 24/7 customer uptime.
(The alternative solution is usually something like "run a mirrored RAID, then take one of the mirrors offline, back it up, and bring it back online." That only works when the RAID implementation isn't constantly being rewritten between every kernel release.)
You cannot apply a technological solution to a sociological problem. (Edwards' Law)
The problem with most suggestions here is that it seems the average slashdot reader is a linux hobbyist or works as the IT manager for a small office that happens to run linux. What happens when you need to backup 6TB/night and don't want to pay someone to sit around swapping tapes all night. Sometimes it just isn't practical to purchase another SAN solution to facilitate an rsync. Or what if you have a collection of high capacity LTO tape drives at your disposal, but don't have the budget for something larger and automated, or smaller with an autoloader. I think automation and efficiency is almost as important as reliability and cost. Not everyone can afford a Storagetek Powderhorn Silo, or needs the versatility of expensive products such as Veritas Netbackup. Then again, sometimes tar or rsync just don't cut it in an enterprise environment where data is mission critical.