As Russell and others have pointed out, TM provides a hybrid of version control and backup. I wonder if it would be feasible to use SVN to manage an entire operating system? You could in essence do hourly commits of '/' with periodic pruning, but I'm sure it wouldn't be as simple as that. Would obviously need to exclude some things like device files. The performance would likely stink big time, too.
Gary On Apr 8, 2013, at 6:48 PM, Russell Standish <li...@hpcoders.com.au> wrote: > On Mon, Apr 08, 2013 at 12:49:47PM -0600, Steve Smith wrote: >> Doug! >> >> >>> Just curious why you Mac guys are buying backup systems, when >>> there is a perfectly good way to use rsync. Here's my nightly >>> backup script, which currently sends my nightly incrementals to a >>> cheap 3TB USB3 external drive: >> >> I occasionally use TM (mostly for my wife) to simply go find an >> event where she deleted or overwrote something she needed. Usually >> I can find in e-mail the date/time of the triggering event, usually >> several days to a few months previous, and then go bumble around in >> the Time Machine until I *see* the (usually a flurry of) changes and >> forensically can figure out exactly *what* changed and *guess* why, >> etc. A point and click later and we are back to the earlier state, >> and if I'm wrong, another point and click and we are at another >> state, and .... > > rsync doesn't solve this particular problem. If I need to do that, I > use a version control system - eg subversion - if my wife needs to do > that, she is SOL :). I'm not going to try to teach her > subversion. Fortunately, that has never happened. > > I have used rsync for about 15 years now, before that using QIC > (150MB) and Exabyte tape storage (4GB). This gives "single spindle" > protection. I have never lost data (well nothing significant, anyway), even > though I have had to restore from backups maybe 5-10 times in that > period due to hard disk failures. > > Time Machine would be nice (provided I could develop trust of > it). Unfortunately, I'm Linux, not Mac, so its not an option :). If > someone implements a transparent copy on write versioning file system, > I'd probably install it on my home partition, just in case I even need > to solve a problem like the above. Subversion is too expensive for > /home. Alas, even though some experimental versions exist, none have > made it to prime time. > > Someone was asking how to do encrypted cloud offsite backups. You can > use gpg for this. In practice, though, I don't see how you could do > incremental backups with gpg in the pipeline, so probably you would > need to maintain another local disk for encrypted data, and then mirror > the encrypted data offsite with rsync. > > Of course, that assume your cloud provider gives you ssh access to > allow the use of rsync. Are there any such enlightened services around? > > -- > > ---------------------------------------------------------------------------- > Prof Russell Standish Phone 0425 253119 (mobile) > Principal, High Performance Coders > Visiting Professor of Mathematics hpco...@hpcoders.com.au > University of New South Wales http://www.hpcoders.com.au > ---------------------------------------------------------------------------- ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com
