How to partition an external hard drive for time machine?

Hello everyone,

I decided to use Time Machine on my MacBook Pro, I've got an external hard drive that I already use for music, movies or important documents, etc.

So what I want to do is to partition my external hard drive in order to get one part for Time Machine and another part for the files I want to keep only on this hard drive and not on my MacBook Pro.

My external hard drive has a storage of 500Gb and the hard drive on my MacBook Pro has 320Gb and I only use 100Gb at the moment.

So which size should I consider for Time Machine in order to partition my external hard drive? I won't back up my whole computer with time machine though, only my personal files and maybe applications too.

And another question do I need to keep the external hard drive always plugged in? Or can I plugged in like once every two days or once a week, etc. just to make the copy, because I don't need it to backup every hours.

Thanks a lot in advance if you can solve this problem

Regards,

The usual recommendation for a TM back up drive is 1.5 times the size of the drive you are backing up, so that it allows room for multiple back ups to be stored. Any smaller and you get into trouble pretty quick, as there isn't room for more than one full back up.
If you only intend to back up a small portion, then 1.5 times the intended back up size, 250GB in your case I would guess.
You don't need to keep it plugged in, no. Time Machine will look for it and if it's not there will back up the next time it's connected. The only issue with that is making sure that you back up when YOU personally need to, when you have altered important files.
If you forget you could render the idea pointless, as you miss vital info.
Given your intentions I would say you'd be fine.

Thanks a lot for your answer Kevriano, what I'll do is to devide my external hard drive in 3 parts: one for a bootable Snow Leopard, one for my personal files and the last one for time machine. I'll think about the size in need to set for each part.

My external hard drive is now in FAT 32, in order to use it on both Mac and PC, I've seen what to set for the OS X portion, I'll keep FAT 32 for my personal files and what about the time machine part?

You must use an OSX partition to backup using TM. The problem? Both TM and Win compatability are important! What I do is this - I have a Win machine on my LAN, so I share space on that machine (a USB drive, on that machine, actually) to the network and use that to share files and use for both Win and Mac backups. Yes, TM will backup to a network drive - here's how...

Time Machine On A Network Drive

Can I simply format my external hard drive in one part for OS-X install, another one in fat-32 for my personal use, and the last part in another format for time machine?

Don't really see the point of having a bootable backup and a TM backup on the same drive - unless, you have some need for retreiving previous versions of files.

My other question, the second partition of personal files, where exactly are those backed up?

Just music, movies, photos or documents, I don't need on my computer because I never use them quite often. For instance; old PSD files I don't need quite often. I'm a photo retoucher, and when I've finish a job for someone, I don't necessarily need it on my computer, that's why I keep it on an external drive if I need it for reference or stuff.

So, if you lose all the files on that partition, that's ok?

not really, I've got movies I may want to watch again.

You can tell TM to not backup whatever files or folders you choose in TM Preferences > Options > + button. Just keep the stuff you don't want backed up in specific folders and add those folders to the exclude list. That way, you can use TM to keep ongoing backups, just like it was designed to do. Soooo many people don't bother to do this, and pay for it later. They post on this forum all the time, but can not be helped.

That's where I was heading. If you have no problem with space, keep that stuff on your internal drive unless you're going to be making duplicate backups of the data. And that means each backup has to be to a different drive. Duplicate or triplicate backups on a single hard drive do you no good whatsoever when that drive fails.

I'd be more inclined to recommend you move everything that you've put on the data partition back to your internal drive unless you're prepared for it all to be gone when that external drive dies - make a single backup on the external using TM, CCC or SD! - Or two backups, one with TM, and a bootable backup with CCC or SD! on a 2nd partition.

That's where I was heading. If you have no problem with space, keep that stuff on your internal drive unless you're going to be making duplicate backups of the data. And that means each backup has to be to a different drive. Duplicate or triplicate backups on a single hard drive do you no good whatsoever when that drive fails.

I'd be more inclined to recommend you move everything that you've put on the data partition back to your internal drive unless you're prepared for it all to be gone when that external drive dies - make a single backup on the external using TM, CCC or SD! - Or two backups, one with TM, and a bootable backup with CCC or SD! on a 2nd partition.