Another Time Machine question

[JEBB]

Earlier I asked about partitions in an external drive to be used with TM ( http://forums.macresource.com/read.php?1,922196 ).

Now I would like to ask how much space would be recommended for an external TM drive (or partition) that is going to be used to back up a 160GB HD?

Thanks

[RAMd®d]

...I've never let that stop me before.

You're backing up the whole (yes, no?) drive, eventually (maybe).

One thing to consider is that as TM runs out of room to store updates, it tosses out the oldest to make room for the newest. Put Gramps on an ice floe, there's a new kid in town.

So the bigger the HD, the farther back in time you can travel.

[GuyGene]

Good question, JEBB, and good answer RAM. I can also use that information. Thanks

[JEBB]

Since TM backs up every file but the System, which itself is quite large, an external drive of 200 to 300 GB should suffice for that 160GB HD nicely, right? Or is that overkill?

[RAMd®d]

Since TM can restore an HD, are you sure that the system is not backed up?

I have no clue as to the inner mechanicians of TM. But unless you're strapped for cash, I'd say there's almost no such thing as overkill.

Ok, maybe a T or two. Given most standard sizes are around 250 and 320, I'd say that's fine.

[Winston]

I agree with RAMd@d that you should be fine with a backup drive which is a "size or two" larger than the source drive. It probably depends some on what kind of files you are using. Someone dealing daily with large Photoshop files might want more backup space than someone dealing with just email, word processing and web browsing, since larger files will fill up space faster if a backup is made every time there is a change in the file (as Time Machine does).

The other reason to get a larger backup drive is that you are likely at some point to fill up the 160 GB drive and want to replace it with a larger one. If you have a larger backup drive you won't necessarily have to replace the backup drive at the same time.

There is typically a "sweet spot" in drive pricing in cost per GB of storage. Right now my impression is that the sweet spot is 320 - 500 GB for notebook drives, and maybe a big bigger for desktop drives. I'll admit I'm not current on drive prices. But for not much more money you should be able to get a drive which gives you some extra flexibility.


Good luck.

- Winston

[modelamac]

You can be selective about what TM backs up. I don't back up anything provided by the OS. I do back up my Home folder. I have a separate drive I use for periodic cloning of my Startup drive.

If my startup drive dies, I can boot from my backup and update/restore it with TM.

[guitarist]

Winston has a point.

Are you using your mac's 160 GB main volume/boot drive to store...everything? Is it pretty full? If you use your boot drive like a giant closet, and throw everything in that closet, then you'll want a larger volume for backup.

My iMac's boot drive is 250 GB. I'm using less than 50 GB of it. But that's just me. (I use external storage too)

In your post, you didn't say how much of your Mac's main 160 GB HD you are using. How full is that 160 GB drive? That would be useful to know.

[mrlynn]

guitarist wrote:
Winston has a point.

Are you using your mac's 160 GB main volume/boot drive to store...everything? Is it pretty full? If you use your boot drive like a giant closet, and throw everything in that closet, then you'll want a larger volume for backup.

My iMac's boot drive is 250 GB. I'm using less than 50 GB of it. But that's just me. (I use external storage too)

In your post, you didn't say how much of your Mac's main 160 GB HD you are using. How full is that 160 GB drive? That would be useful to know.

But if you are using an external drive for your giant closet (unless you're not a pack rat like most of us, you do want a giant closet or three, right?), then you want to back that up, too. So you will want even more room for TM.

I have a 160 GB internal drive in my MBP, and a 320 GB external, of which I back up maybe 100 GB. It all filled up a 1 TB TM drive pretty quickly. I'd say, get as much drive as you can afford.

/Mr Lynn