Backups in OSX

[tongodeon]

If you have a mac, you have no excuse to not keep backups because it is cheap, fast, and incredibly easy.

1. Go to the computer store of your choice and buy an external hard drive at least as big as the one in your system.
   
2. Open /Applications/Utilities/Disk Utility.app
   
3. Using Disk Utility, format the external hard drive HFS+ and name it "External".
   

Comments

[mkb_cbr]

Unfortunately, there is a bug in Apple's rsync that prevents the -t flag (implied by -a) from working when -E is also invoked. On the destination volume, you end up with modify times matching when each file was backed up rather than the modify time of each original file.

The upshot of this is you end up running a full backup each time instead of an incremental.

The workaround seems to be using this guy's patch or installing Rsyncx. Rsyncx has its own quirks, but I was in a hurry so that's what I'm using until I've taken care of some other issues.

I have used unison to do two-way synchronization of big source trees and it works great. It's is reliable and efficient, even over Wifi->VPN->DSL->big_corporate_network->server. Unfortunately, unison is much slower than rsync when copying my entire drive.

Also, I can't print.

[tongodeon]

there is a bug in Apple's rsync that prevents the -t flag (implied by -a) from working when -E is also invoked. On the destination volume, you end up with modify times matching when each file was backed up rather than the modify time of each original file.

The upshot of this is you end up running a full backup each time instead of an incremental.

I can't reproduce your bug. I'm doing incrementals. Granted it seems to be transferring some files it shouldn't be, but on the whole I'm still saving a ton of time.

sent 256632046 bytes received 20500 bytes 1523160.51 bytes/sec
total size is 41261212684 speedup is 160.77

[mkb_cbr]

Interesting. What OS version and hardware are you on? I'm on a 10.4.4 15" PB 1.5GHz replicating over ssh to an external drive on a 10.4.4 Mini.

I can confirm that the time bug was affecting every file for me. I just know that I was transferring some files which hadn't changed, and when I compared to the destination volume I found that the mod times were wrong. I've also turned off the ignore ownership option on the external.

On a slight tangent, I still haven't arrived at an appropriate set of excludes. Are you doing any file exclusion? I'm using --delete-excluded and just noticed that because of that I might be inadvertently re-enabling Spotlight indexing on the destination volume. Still need to investigate that one.

[tongodeon]

You might be on to something. Here's normal linux:

[soren@lynx test]$ ls -al foo
total 412
drwxrwxr-x 2 soren soren 4096 Feb 4 21:05 .
drwxrwxr-x 3 soren soren 4096 Feb 4 21:09 ..
-rw-r--r-- 1 soren soren 409305 May 29 1975 words
[soren@lynx test]$ mkdir bar
[soren@lynx test]$ rsync -av foo bar
building file list ... done
foo/
foo/words
wrote 409484 bytes read 36 bytes 819040.00 bytes/sec
total size is 409305 speedup is 1.00
[soren@lynx test]$ ls -al bar/foo
total 412
drwxrwxr-x 2 soren soren 4096 Feb 4 21:05 .
drwxrwxr-x 3 soren soren 4096 Feb 4 21:09 ..
-rw-r--r-- 1 soren soren 409305 May 29 1975 words

And here's OSX:

gpb:/Volumes/test soren$ ls -al foo

[mkb_cbr]

The dude with the patch says "These bugs and fixes have been reported to Apple." Hopefully they are on the motherfucker and sending the Wolf.

[tongodeon]

Might be worth filing a report anyway. They probably fix bugs in order of most-reportedness.

[mkb_cbr]

Erk. That reply should have opened with "I can't confirm."