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Foxdog175 · Nov 5, 2007, 01:26 AM

Do you need 100% of your current HD space for Time Machine to function well? I've got 2x230gig internal drives and I would like to partition one of them to donate 60 gigs to Time Machine. Will this be sufficient or will that not be able to back up my changes for very long?

I don't really understand how it works. From what I've read, it backs up only data that gets changed? Say, I have around 200 gigs of data that could actually be changed (most of it is entertainment media that shouldn't be changed). With 200 gigs manipulatable data, how much space would Time Machine need to keep backups lasting a month (or several)?

I did try to do a live partition in Leopard, but it keeps failing with an error:

"Partition Failed
Filesystem resize support required, such as HFS+ with Journaling Enabled."

I did a quick Google search which came up with this long thread of people having the same issue. Is live partitioning broken for the majority of drives (even ones Apple puts into stock machines, like mine)?

The thread can be viewed here:

Apple - Support - Discussions - disk utility: problem with resizing a ...

iDaver · Nov 5, 2007, 02:40 AM

Originally Posted by Foxdog175

From what I've read, it backs up only data that gets changed?

TM backs up all of your data from any or all disks. (You can choose which disks not to back up in the system preference panel.) After the full backup, TM backs up once per hour, anything that is new or has changed. Then it keeps a daily backup of new stuff or changed stuff for a week. I can't remember where it goes beyond that but eventually it starts dumping the older stuff which has been changed when you run out of backup disk space.

So, you need enough space on the backup disk to hold all of the data on at least one disk (or partition) plus enough extra for expected new stuff and changed stuff. I hope that makes sense.

I have about 100GB of data on my boot drive. I'm using a 160GB drive for backup. I figure I'm covered for two or three years, unless I collect a whole lot of new stuff.

I'm undecided if I really like TM. I don't like it kicking in every hour. I wish there was a preference to have it backup once a day or twice a week. I guess I'll just leave it turned off most of the time, and turn it on periodically.

MacosNerd · Nov 5, 2007, 10:11 AM

Its not just the data that gets backup but your drive, i.e., applications as well as your data.

I pleasantly surprised to see that everything was backed up (I viewed the contents of the backup file).

You can select any folders that you wish not to back up, such as the application folder so you have a fair amount of flexability.

TETENAL · Nov 5, 2007, 12:22 PM

I would say your Time Machine drive should be at least 50% larger than your internal hard disk.

iDaver · 02:24 PM

Originally Posted by MacosNerd

Its not just the data that gets backup but your drive, i.e., applications as well as your data.

True, I used the word data earlier when I suppose I should have used the word "files" or "stuff." If you have a 160GB boot drive but there is only 50GB of "stuff" on it, including applications, you don't necessarily need a 160GB Time Machine backup drive, until you start to collect more "stuff."

I would say TETENAL has a good estimate that your backup drive should be about 50% bigger, but I'd say, "bigger than the total of the stuff you need to back up." Of course, you should always plan for the future and assume you'll have twice as much stuff in a few years. If you're buying a new backup drive, get a big one!

Foxdog175 · Nov 5, 2007, 02:03 PM

Could anyone recommend a hard drive to backup up 500 gigs using Time Machine? Most of the external HD's I've seen aren't even 500g.

Kenneth · Nov 5, 2007, 02:17 PM

I will not rely on partitioning a drive for Time Machine. A dedicated hard drive is pretty much a must-have for Time Machine.

Originally Posted by Foxdog175

Could anyone recommend a hard drive to backup up 500 gigs using Time Machine? Most of the external HD's I've seen aren't even 500g.

There are 750GB or lager external drives out there. How about pick your own size of hard drive and your choice of hard drive enclosure?

Foxdog175 · 04:40 PM

750G would be nice. I don't know all that much about external HD differences...like seeing a 320G G-Tech drive for $199 and a 500G Lacie drive for $219. For the sole purpose of Time Machine, would I need something really high-tech? What is the difference in drives when shopping around? Just speed?

What about something like this? The Apple Store (U.S.) - Iomega 500GB Hi-Speed USB 2.0 Desktop Hard Drive

Of the 466G, I'm only using a little over 350G. 500G should cover that, shouldn't it? I just deleted over 100G of junk on my computer in the last few weeks, so I don't think I'll have a problem hovering around 350G of usage. How long would I get with 350G of data being backed up on a 500G HD? In other words, how many months (years?) would Time Machine backup?

JustinHorne · Nov 5, 2007, 04:44 PM

[QUOTE=Foxdog175;3525821]
What about something like this? The Apple Store (U.S.) - Iomega 500GB Hi-Speed USB 2.0 Desktop Hard Drive
/QUOTE]

I picked up that exact drive a week ago for TM
It works quite well. It's a little louder than my 500 GB Western digital, but it works perfectly fine. I mean, it's a hard drive, and it hasn't died yet, so that gives it a thumbs up from me.

Big Mac · Nov 5, 2007, 05:36 PM

People around her say to stay away from Lacie. It used to be a quality Mac brand, but many have had problems with them apparently.

iDaver · Nov 5, 2007, 05:55 PM

Originally Posted by Foxdog175

What about something like this? The Apple Store (U.S.) - Iomega 500GB Hi-Speed USB 2.0 Desktop Hard Drive

Of the 466G, I'm only using a little over 350G. 500G should cover that, shouldn't it? I just deleted over 100G of junk on my computer in the last few weeks, so I don't think I'll have a problem hovering around 350G of usage. How long would I get with 350G of data being backed up on a 500G HD? In other words, how many months (years?) would Time Machine backup?

That's a nice price for a big drive. I tend to stay away from USB-only drives. FW400 is a good bit faster. However, since Time Machine backs up incrementally, you won't be transferring huge amounts of data to it on a regular basis; so USB might be just fine.

I'd say you'll be fine with a 500GB drive if you can continue not to collect junk you don't need.

Kenneth · Nov 5, 2007, 07:24 PM

Originally Posted by Big Mac

People around her say to stay away from Lacie. It used to be a quality Mac brand, but many have had problems with them apparently.

I have no problem with my LaCie CD/RW burner and d2 external drive. Guess I'm lucky.

Sure, you have plenty of choice nowadays for external hard drives.

Foxdog175 · Nov 5, 2007, 08:33 PM

Thank you all for the feedback. I really appreciate it. How loud is the HD? Is it always loud or only when transferring large amount of data?