Time Machine and AppleScript

cirno · August 21, 2007, 6:21am

Is it possible to do similar back up than Time Machine and QRecall do? I mean if file is changed only little, then only changed part is back upped, not entire file. It would be nice to do this type of back ups for some big folders.

StefanK · August 21, 2007, 7:31am

Hi,

do you want
¢ differential, only the changes will be copied
or
¢ incremental, only the changes will be copied and all old versions will be kept.

A differential backup can be easily done with the rsync shell command

cirno · August 21, 2007, 2:01pm

I think incremental would be better but differential is ok too.

Time Machine and QRecall is incremental?

And i mean Time Machine/QRecall type of back up, not normal back up.

Bruce_Phillips · August 21, 2007, 5:27pm

I feel that’s poorly stated.

Quoting from Microsoft’s Encyclopedia of Networking:

differential backup:

A backup type in which the only files and folders that are backed up are those that have changed since the last normal backup occurred.

Overview
… You can use differential backups in conjunction with normal backups to simplify and speed up the process. If a normal backup is done on a particular day of the week, differential backups can be performed on the remaining days of the week to back up the files that have changed since the first day of the schedule. Differential backups are faster than normal backups and use less tape or other storage media.

Notes
Differential backups are cumulative (unlike incremental backups), so when you need to do a restore, you need only the normal backup and the most recent differential backup. Differential backups take longer to complete than incremental backups, but you can restore data from them faster.

incremental backup:

A form of partial backup used in between normal backups during a backup cycle.

Overview
In an incremental backup, only those files and folders that have changed since the last normal backup are backed up. … Incremental backups are typically used in conjunction with normal backups to simplify and speed up the overall backup process. If you do a normal backup on one particular day of the week, you can perform incremental backups on the remaining days to back up only the files that have changed during each day of the backup schedule. Incremental backups are faster than normal backups and use less tape.

Notes
Incremental backups are not cumulative, as differential backups are, so when you need to perform a restore, you need the normal backup and all incremental backups since the normal backup was done. Incremental backups are faster to perform but take longer to restore.

(Emphasis added.)

StefanK · August 21, 2007, 5:37pm

Thanks, I’ve only tried to adapt to cirno’s short style

cirno · August 23, 2007, 6:54am

This is what i’m looking for. Another short answer.

Kevin_Bradley · August 23, 2007, 4:02pm

Stupid question (I got a million of 'em!): Isn’t Time Machine (from the sound of it) just a clever front end for a version control system? It sounds a lot like Subversion of CVS to me, with the data base acting as your backup and put on another drive.

Qwerty_Denzel · August 23, 2007, 11:05pm

From what I know Time Machine utilizes the same technology that Spotlight uses to monitor changes in the file system. I think it was said that it backup entire files, but that might have changed now.