Article:		Automated Backups on Tiger Using rsync
Subject:		7 day incremental backup
Date:		2005-09-30 06:54:17
From:		annibee
Hi I love this tutorial and I've had a lot of fun scheduling various backups from applescript in ical. Its funny how the MACOSX wrapping seems to make everything easier than say using perl in UNIX ;) Anyway my question is ..... How do I implement a full backup every Sunday and then incremental backups everyday at midnight using applescript and ical or should I just script the whole thing as listed on http://rsync.samba.org/examples.html Thanks in advance Anna :)

Showing messages 1 through 3 of 3.

• 7 day incremental backup
  2005-10-01 09:26:01  Corvus [View]
  
  
  Hi Anna. I guess I wasn't clear on how rsync works; it creates
  full backups by copying only the data that has changed since the last backup.
  You don't need to do "full" backups ever again.
  

  
  Suppose you ran rsync for the first time on Sunday and it
  made a copy of your entire 80 GB hard drive. You work on some projects;
  changing a few bytes in a multi-megabyte database, add a few lines to a
  text file, add and delete some records from a contact list. When rsync
  runs again that night, it will compare each file on your hard drive, byte-for-byte,
  with that on the backup drive, and only copy over the bytes that have changed.
  Only the few bytes changed in your database get copied to the backup.
  The new lines get added to the backup's copy of your text file, the new
  contacts get added to your contact list and the old ones get deleted, without
  affecting any of the other records. rsync makes the fewest
  changes to the target files so they are identical to the source files. It really
  obsoletes the old full/incremental backup method.

• 7 day incremental backup
  2005-12-01 07:10:34  KevinStout [View]
  
  
  Hi Corvus,
  
  You seem to be missing the point of an incremental backup. The point is to be able to do a restore to a point in time. For example you deleted / changed a critical file on tuesday, but do not realize it until friday. From waht I understand, if you rsynced everyday, the orginal or unchanged file is now lost forever.
• 7 day incremental backup
  2005-12-01 07:10:21  KevinStout [View]
  
  
  Hi Corvus,
  
  You seem to be missing the point of an incremental backup. The point is to be able to do a restore to a point in time. For example you deleted / changed a critical file on tuesday, but do not realize it until friday. From waht I understand, if you rsynced everyday, the orginal or unchanged file is not lost forever.