how much space does Time machine take up?

[bumzo1]

I am looking at buying a new Hard drive and need to know how much space TM takes up. Currently I have about 150gb filled on my main drive all of which I plan to back up. How exactly does TM work? The reason I am asking is because I have found a nice HDD but there is a $75 difference in 1tb and 500gb. I also plan on dedicating about 150gb as a place to store my movie files. So would 350gb-formatting be enough space to back up my 150gb (well 100gb once I move the movie files) for a decent amount of time? (2-3 weeks?)

Thanks for the feedback I've only been on leopard for about 4 months (from tiger) and don't know how TM works.

 

[todd2000]

So would 350gb-formatting be enough space to back up my 150gb (well 100gb once I move the movie files) for a decent amount of time? (2-3 weeks?)

Thanks for the feedback I've only been on leopard for about 4 months (from tiger) and don't know how TM works.

In a word yes. You will have the initial 100GB of data for the first back-up, and then it will backup just the files that change every hour. So unless you do a LOT of editing of VERY large files, 350GB will be plenty. Most people recommend about 2X the size of the drive your backing up for a TM drive

 

[bumzo1]

ok thanks I thought it worked that way but I wasnt completely sure. I think I'll go with the 500gb and save $75

 

[FSMBP]

Yeah the 500GB one would be fine. Remember, Time Machine backs EVERYTHING up UNLESS you tell it not to.

I only back up my files (ex. Music, Movies, Documents) not the System Files (which can be as large as 10-20GB).

The only drawback about not backing up system files is that if something terrible happens, like Mac OS X won't start, you can't restore your Mac to the way it was via Time Machine - you'd have to reinstall Leopard, then manually drag your backed up files to the harddrive.

 

[Steve-M]

I am looking at buying a new Hard drive and need to know how much space TM takes up. Currently I have about 150gb filled on my main drive all of which I plan to back up. How exactly does TM work? The reason I am asking is because I have found a nice HDD but there is a $75 difference in 1tb and 500gb. I also plan on dedicating about 150gb as a place to store my movie files. So would 350gb-formatting be enough space to back up my 150gb (well 100gb once I move the movie files) for a decent amount of time? (2-3 weeks?)

Thanks for the feedback I've only been on leopard for about 4 months (from tiger) and don't know how TM works.

When you assign Time Machine a drive to use, it will start by backing up your entire system. From that point on TM will make hourly backups, daily backup for the past month, and weekly backups until your disk is full. At the point of your disk being full, the older files are over written.

We have a 500 GB external hard drive. I used the disk utility to split the drive into two equal partitions. The first was formatted to Mac OS Extended (Journaled) so it could be used with TM. The second was formatted FAT so it could be used by any OS. In our case, Mac, linux, and windows.

250 GB seems to be more than enough for TM, and our situation.