RobertDeveloper wrote:
. . .
If I wanted to restore the latest backup, time machine would have to go through the whole history.
No, it doesn't. It just uses the date-stamped backup folder you select (the same one it uses to display the backup in the "Star Wars" display. It won't take any longer if there are lots of backups vs. only a few.
You might want to review How Time Machine works its Magic for an explanation.
I would like to keep it under 100GB
The only way to do that is to limit the amount of space available, by making the partition smaller. But why do that if you don't need to?
In any case I don't see why I should keep 6 months long history of incremental backups.
It won't hurt anything. I occasionally go back farther than that looking for an old email I deleted, or file I changed several months ago.
Using backup every hour would be overkill. Not because any backup performance issues, it is pretty fast and as a user I don't even notice that the backup is running on my Macbook Air, but I'm concerned how I would find older copy of a file in time machine if it was doing backup every 1 hour. I don't know if I could easily compare 2 files from different points in history.
Usually there's no reason to do that. If your HD fails, you restore the most recent one (unless you suspect damage, and want to pick an earlier one).
To find each version of a file, you're supposed to be able to do that by selecting it in the "Star Wars" display, then use the arrow keys. See Time Machine - Frequently Asked Question #15. Some folks say that doesn't work for them, but it usually seems to.
Or, use the 3rd-party Backup Loupe app. See #A2 in Time Machine - Troubleshooting
Is there a way to compare files and even entire directories? Let's say I need to compare all files on the entire har drive from yeaterday and a week ago (or a month). Is it even possible?
Time Machine won't, except to find differences with the arrow keys as above. Backup Loupe (and Time Tracker) will only compare a selected backup to the previous one.
If you're comfortable with UNIX and Terminal, the new tmutil command has a compare verb that might do part of what you want.
Or does time machine only allow to roll back the whole drive.
No. You can restore selected items, via the "Star Wars" display as noted above.
If I could compare files (for example source code) and see differences and then revert back only files I need, that would be perfect.
That's tough because the "Star Wars" display takes up the whole screen; you can't put two windows side-by-side. But you could go directly into the backups and do that via the Finder.
If the app you use supports Versions, the Versions Browser can do that, sort of.
Is it possible to use Time Machine with /Developer/Applications/Utilities/FileMerge.app?
You can't alter anything in the backups. I don't know if that app will let you read from them or not.
Message was edited by: Pondini - typed calculatedrift when I meant compare (senior moment)
