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Time-Machine-style backup with rsync

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Re: Time-Machine-style backup with rsync

#21

Post by pudquick »

hnha wrote: post #12
ta_tmachine wrote: post #6

When will this trend of "like time machine" backup software going to stop ? Time Machine, as can be seen here http://www.apple.com/support/timemachine/ time machine is tightly integrated in the os and provides a self-defining interface and user experience. This github page is for a wrapper shell script around rsync, which is not like time machine. This has been going on for a while now, see Timevault ( https://wiki.u…

Please elaborate on what you are missing from the wanna-bes

I would guess something like this:

http://www.youtube.com/watch?v=RDPzVdohrck#t=1m13s

Oh, and integration with the OS X recovery partition / OS reinstallation mechanism that allows you to point to a Time Machine backup as the recovery point for your re-installation.

Re: Time-Machine-style backup with rsync

#22

Post by quesera »

The key feature of Time Machine is hard links to directories -- which is only possible on modern HFS+ (and rsync doesn't even try). Some people like the UI too, of course.

Without hard linked directories, a full --link-dest backup of a decent sized disk, with zero file changes from the previous pass, can easily consume 100MB (and take 45 minutes to perform).

This disk consumption might seem insignificant, today, but that's 2.4GB per day if you run a standard Time Machine equivalent backup schedule. Of course you might not choose to do that, because the previous hour's backup would only finish 15 mins before the next one started, which is insane.

These numbers are from direct experience on a 2TB, approximately 60% utilized source drive.

That said, I use rsync, not Time Machine, for my OSX backups. You'll want a few additional switches for HFS+, and if your target drive is HFS+ also, make sure you turn OFF "ignore ownership on this volume" in the Finder... but the script posted here has the right general idea. Somewhere on my project list is adding directory hardlinking to rsync.

Re: Time-Machine-style backup with rsync

#24

Post by icarus_drowning »

pudquick wrote: post #21
hnha wrote: post #12

Earlier quoted context omitted.

Please elaborate on what you are missing from the wanna-bes

I would guess something like this: http://www.youtube.com/watch?v=RDPzVdohrck#t=1m13s Oh, and integration with the OS X recovery partition / OS reinstallation mechanism that allows you to point to a Time Machine backup as the recovery point for your re-installation.

The integration with OS reinstall works very well, and is pretty seamless from the user's perspective. I used to do two backups-- a local TM backup and a separate cloud backup, but I found it was actually easier to just use Automator to up mount my TM volume once a day, image it, and send that up to the cloud. When my TM volume failed last year, I just pulled the latest image and put it on a replacement drive, and I was back up and running.

TM has had a few problems, but by and large it is one of the quiet successes in OS X, and probably my favorite feature if the OS. Why Microsoft hasn't put something like it in Windows is baffling to me.

Re: Time-Machine-style backup with rsync

#25

Post by ilikejam »

greglindahl wrote: post #20
ilikejam wrote: post #19

Earlier quoted context omitted.

Depends if the backup's on the same filesystem as the source.

You don't want to hard-link backups to the non-backup copy -- the non-backup files might change, and if it is a change that doesn't remove the file first, it will modify the backups if the backups are hard linked. Doesn't vim intentionally do this if it edits files that are hard linked? emacs breaks the hard link. I'm not saying either behavior is best, but in this case one might be surprising!

Good call.

Re: Time-Machine-style backup with rsync

#26

Post by tunesmith »

ta_tmachine wrote: post #6

When will this trend of "like time machine" backup software going to stop ? Time Machine, as can be seen here http://www.apple.com/support/timemachine/ time machine is tightly integrated in the os and provides a self-defining interface and user experience. This github page is for a wrapper shell script around rsync, which is not like time machine. This has been going on for a while now, see Timevault ( https://wiki.u…

I love/hate Time Machine and would love to switch to something better. The problem is that to be secure, you need both versioned backups and redundant storage of the backup. Time Machine has trouble with network volumes (this doesn't stop me from using my DroboFS but I have to struggle with it regularly). It also doesn't have a cloud backend. Best option to have both is Crashplan, but the UI sucks. So if there's anyone else like me, we're regularly in the market for considering options that offers all of redundancy, version history, and a solid UI.

Re: Time-Machine-style backup with rsync

#27

Post by gizmo686 »

quesera wrote: post #22

The key feature of Time Machine is hard links to directories -- which is only possible on modern HFS+ (and rsync doesn't even try). Some people like the UI too, of course. Without hard linked directories, a full --link-dest backup of a decent sized disk, with zero file changes from the previous pass, can easily consume 100MB (and take 45 minutes to perform). This disk consumption might seem insignificant, today, but…

What is the benefit of hard-linking directories relative to soft-linking them?

Re: Time-Machine-style backup with rsync

#29

Post by laurent123456 »

quesera wrote: post #22

The key feature of Time Machine is hard links to directories -- which is only possible on modern HFS+ (and rsync doesn't even try). Some people like the UI too, of course. Without hard linked directories, a full --link-dest backup of a decent sized disk, with zero file changes from the previous pass, can easily consume 100MB (and take 45 minutes to perform). This disk consumption might seem insignificant, today, but…

The --link-dest option of rsync, used in this project, actually creates hard links.
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