Les Mikesell wrote:
On Wed, 2006-06-14 at 13:09 -0400, Bowie Bailey wrote:
I am looking for a simple backup program that I can use to backup a CentOS box to a local tape drive.
I used that for years, but the network grew and needed a "bigger" solution so I switched to backuppc which is working great.
I'm using backuppc. I just need something to dump the backuppc machine to tape for an offsite or last-resort backup. The problem is that backuppc is currently using 161GB (compressed) and the tapes only hold 40GB each, so I need something with some sort of intelligent tape-spanning capability.
You are going to have more trouble than that. Backuppc will have millions of hardlinks in that 161GB and nearly all file oriented backup programs will take an impractical amount of time to deal with them. And restoring will be even worse - basically everything ends up building a table of inode numbers and scanning it for a match on every hardlink.
True, but this will only be used as a last-case scenario for restores, so in that case I'm willing to wait a bit.
I haven't seen flexbackup. I'm currently evaluating afbackup.
You really want a matching external hard drive so you can dd an image copy to it. There has been quite a bit of discussion on this topic on the backuppc mail list and I'm not sure anyone has come up with an ideal solution. Or, you can use the 'archive host' feature of backuppc to generate tar images of backup runs optionally compressed and split to fit your media, but these are copies of individual hosts and you loose the pooling feature.
I agree that hard drives are faster, larger, and cheaper than tapes, but I can drop a tape onto a concrete floor and reasonably expect it to work afterwards. A hard drive might still work, but I wouldn't want to bet on it.
On Wed, 2006-06-14 at 12:45, Bowie Bailey wrote:
You are going to have more trouble than that. Backuppc will have millions of hardlinks in that 161GB and nearly all file oriented backup programs will take an impractical amount of time to deal with them. And restoring will be even worse - basically everything ends up building a table of inode numbers and scanning it for a match on every hardlink.
True, but this will only be used as a last-case scenario for restores, so in that case I'm willing to wait a bit.
Try it before you need it. I'll guess that 'a bit' will turn out to be at least several days.
You really want a matching external hard drive so you can dd an image copy to it. There has been quite a bit of discussion on this topic on the backuppc mail list and I'm not sure anyone has come up with an ideal solution. Or, you can use the 'archive host' feature of backuppc to generate tar images of backup runs optionally compressed and split to fit your media, but these are copies of individual hosts and you loose the pooling feature.
I agree that hard drives are faster, larger, and cheaper than tapes, but I can drop a tape onto a concrete floor and reasonably expect it to work afterwards. A hard drive might still work, but I wouldn't want to bet on it.
Yes, the trick is to have 2 or more of the external drives so you'd have to drop them both at once - and don't ever put them in the same place - that is, don't bring back the previous copy until you've made the next one. I set up amanda years ago and still let it make tapes for offsite storage because it is mostly automatic, but I haven't restored from tape since starting to use backuppc and hope I don't ever have to again.
On Wed, Jun 14, 2006 at 02:37:16PM -0500, Les Mikesell wrote:
On Wed, 2006-06-14 at 12:45, Bowie Bailey wrote:
You are going to have more trouble than that. Backuppc will have millions of hardlinks in that 161GB and nearly all file oriented backup programs will take an impractical amount of time to deal with them. And restoring will be even worse - basically everything ends up building a table of inode numbers and scanning it for a match on every hardlink.
True, but this will only be used as a last-case scenario for restores, so in that case I'm willing to wait a bit.
Try it before you need it. I'll guess that 'a bit' will turn out to be at least several days.
replying late to this thread - but i definitely concur with Les. You will NOT be happy with the restore performance for any file-based backup utility you try to use on your backuppc file store.
My suggestion if you really want to back up to tape (which i generally agree is a good idea) is unmount the filesystem and back up the raw device. Or use LVM snapshots to do that, or whatever. i use solaris for backuppc so i use ufs snapshotting.
You might first fill the free space on the disk with a bunch of highly-compressible data (eg, dd if=/dev/zero of=fnord bs=1M count=1024 to create a 1G file of nulls). that will allow your tape drive's compression, or gzip or whatever, to get the best out of it.
In addition to backuppc we use veritas netbackup. I've been considering buying the veritas "advanced client" which will do incrementals of raw devices. you probably don't want to go down the netbackup route if you don't have it already but you might check for similar solutions.
btw, Les mentioned "an identical hard disk" as your backup copy. It doesn't have to be really identical, just as big or bigger than the backup store.
danno -- dan pritts - systems administrator - internet2 734/352-4953 office 734/834-7224 mobile
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Bowie Bailey -
Dan Pritts -
Les Mikesell