Requirements to run Time Machine

The first backup copies almost everything on your system (except a few system caches, trash, etc.), so will be quite lengthy.

Unless you have some other process using most of your CPU, or something that's also using the TM drive, the process will be bound mostly by the speed of the connection, and how much data is on your internal HD. USB is slowest, FireWIre 400 next, FireWire 800 fastest.

Allow an hour or two as an extremely rough guess. You can use your Mac normally while this is going on without a problem unless, of course, you're doing something very intensive.

After that, most of TM's hourly incremental backups should be very quick, quite possibly less than a minute, unless you've made a lot of changes or additions, or are using some features or apps (mostly 3rd-party) that can cause big backups.

Otherwise, any Mac that can run Leopard decently will hardly notice TM at all.

How big a partition did you make on your external drive? The general rule of thumb is, TM needs 2-3 times the space of the data it's backing-up, to provide a reasonable "depth" (age) of backups. This varies greatly, of course, depending on how you use your Mac.

You might want to review this: http://www.apple.com/findouthow/mac/#tutorial=leopardtimemachine

and this: http://www.apple.com/macosx/features/timemachine.html

and perhaps this: http://discussions.apple.com/thread.jspa?threadID=1964018

bigt2003 wrote:
I partitioned the external harddrive to be exactly divided in half, that being 125 GB apiece

If your internal HD has roughly 40 GB or less, and you don't expect it to grow much past that, then you should probably have enough space. If not, or if you add or change a lot of big files frequently, you may not.

Also a note: You should exclude that other partition from TM, via TM Preferences > Options, and if you don't have that data backed-up separately, strongly consider doing so.

bigt2003,

Did you use the first partition, or the second for your Time Machine backup? If you are not certain what I mean by this, the "first" partition is the one that would have been at the top of the graphical representation of volumes in Disk Utility''s "Partition" pane, when you were partitioning.

I ask this, because you can delete the second partition at any time in the future, in order to expand the first volume without destroying its data, if it ever becomes necessary to do so for your Time Machine backups.

If you only have around 40 GBs used on your internal drive, the current 125 GBs on the external should be enough indefinitely. When the volume fills up, Time Machine will begin automatically removing the oldest backups and "thinning" the ones in between, as necessary to create more room for new backups. If you begin using significantly more than that 40 GBs, however, you may run into problems. I would put the "break point" at around 60 GBs or so. At that point, you might consider enlarging the Time Machine backup volume.

Scott

bigt2003 wrote:
i mean i have 160 GB of space on my internal hard drive, with 110+ available.. my external hard drive is the one i partitioned.. it's 250 GB and i dedicated half for time machine and the other for various programs.. i have two hard drives on my computer.. i'm talking about strictly my external one

Yes, that's what I thought. You should be fine, unless your internal grows a lot (they have a tendency to do that!)

But do back-up (copy) the programs and whatever else is on the other partition, as your external can fail, just like your internal. Always have (at least) two copies of anything important, in two different places. DVDs work fine for things that don't change frequently, but they don't last forever.

bigt2003 wrote:
should i get two external drives to be safe?

It all depends. As long as you have (at least) two independent backups of everything important, in two places, you should be ok for local backups.

This is not a "one size fits all" sort of thing. What's good for me may not be for you.

I'm not sure why you're putting game programs, etc., on your external drive. Usually folks do that because there isn't enough space on their internal HDs, but it appears you have plenty. Do note that your internal should always have at least 10% available (15% -20% is better) for OSX to use.

Also note that a program running on an external disk, or with it's data on an external disk, will be slower than if on your internal HD.

So you might be better off putting all your "originals" on your internal HD and using the external just for TM.

You might also want to think about getting a portable external, to take off-site, to your safe deposit box, workplace, relative's house, etc. As great as external drives are, they may not protect you from fire, flood, theft, or direct lightning strike on your power lines. This could be another TM backup, or a "clone" of your whole internal HD, or just a copy of, say, your home folder. If you update it periodically, say once a week, you're pretty well protected.

Some folks actually get a pair. They use one with TM for a week or so, then take it off-site and swap it with the other one. You do have to tell TM when you swap, via TM Preferences > change disk, and you shouldn't go much beyond about 10 days between swaps.