How much back-up memory do I need?

Hi amember;

I guess it all depends on how you plan to do your backups. What software do plan to use?

Allan

If you intend to use Time Machine, the bigger the drive you have, the longer you can keep your backups.

If you'd be backing up your data another way, such as using CarbonCopyCloner or SuperDuper! to clone the internal drive to the external, you would only need one the same size as the internal drive, but larger would also work fine.

If you can get a good deal on that large drive, go ahead and get it!

~Lyssa

Two to three times the data you are backing up is the norm. A 500 GB drive would be fine, I think. You could always partition the 1 TB drive and use half as TM and half for other storage like iMovie projects and such.

Hey. For some good advice on backing up, I suggest you check out some of the articles over at http://www.tekserve.com/service/mac-faq/backingup/. Specifically, you may want to look at http://www.tekserve.com/service/mac-faq/backingup/back-up-data.php, http://www.tekserve.com/service/mac-faq/backingup/backup-strategies.php, and http://www.tekserve.com/service/mac-faq/backingup/reformat-partition-drive.php. Those articles will help you choose how you want to back up, as well as describe how to set up an external hard drive for backup purposes. Good luck!
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Jeremy A.
Tekserve Intern


*As an intern at Tekserve, I may receive financial compensation for my recommendations and links *

<Edited by Host>

Just an aside, "memory" is RAM, not harddisk space. Sometimes the terms we use are very important.

amember wrote:
I'm using about 100 Gigs of my 160 Gig drive. I don't have anything very complicated I need backed up. I got a 320 Gig Seagate back-up hard drive....is that enough?

If you're planning to use Time Machine, almost certainly. The general rule of thumb is, TM should have 2-3 times the space of what it's backing-up, but that varies greatly depending on how you use your Mac. See item #1 of the Frequently Asked Questions post at the top of the Time Machine forum.

If you're not sure about Time Machine, you might want to review the Time Machine Tutorial

and Time Machine Features

and perhaps the other items in the FAQ referenced earlier.

I would think 320 is plenty. The thing that matters after the initial backup (which will take a little more than the 100GB), is what files you change regularly. If you don't create or edit very large files multiple times a day, the incremental backups won't use much of the space and you will be able to go quite a while before TM tries to thin the older backups.

However, there are some things that you need to watch out for. If you use Entourage, it stores its data in a single database file. So everytime you get a new email, TM will back up the entire database file. Also, programs like VMWare Fusion and Parallels Desktop store the virtual machine file as a single large file. So, once again, even a small change in the Windows environment will flag TM to make another backup of the entire file. There isn't a good way around this. I exclude those things from Time Machine. I don't back up the VM because I don't care about what I have in them. You could manually back it up weekly to prevent TM from gobbling up your hard drive space with multiple near-identical files.

Based on that usage, 320GB will be fine.

amember wrote:
All of you are SO helpful. I love this Forum for that reason. You guys are not just smart

Not so much (in my case, anyway). It's just that we've learned, often the hard way!

I wouldn't even mind if once a week it backed up everything and got rid of its other backups, as long as it's got a current one in there.

99% of the time, that would be fine with most of us. Until we change or delete the wrong thing, use Save instead of +Save As,+ or find that a file's been corrupted. Then being able to restore a previous version from a couple of hours earlier, in a matter of a minute or two from Time Machine . . . whew, what a relief!

Or until our internal HD fails (and they all do, eventually). Then realizing all we have to do is get the disk replaced, then re-load the entire system from a TM backup; instead of installing OSX from the Leopard Install disc, then load the updates, then find and re-load all our 3rd-party apps (hope we have a record of purchase keys!), re-do the configuration, set-up email again, re-set preferences and settings, pray for the data, . . . priceless!