Is a 1Tb external TimeMachine enough...

[KevKaos]

Is a 1TB external drive large enough to use as a TimeMachine backup for a 1TB iMac? I ask because I may have screwed up. I have already placd an ordr for a 1TB external drive, thinking that is what I am going to use for my TimeMachine backups. Last night I was reading my "Switching to the Mac" book and it said to use Timemachine, your back up drive needs to be adt least as large as the disk you are backing up. Obviously, these are same size, but have I shot myself in the foot? I hate sending things back, so worst case, I now have a 2TB iMac I guess. If this external is really to small for its intended use, what size drive should I be looking for? Sorry if this is a really basic question, but I'm a Mac noob. Thanks.

 

[viggen61]

I seem to recall that Apple recommends a hard drive used for a Time Machine backup be at least 2x the size of the drive you are backing up.

But, unless you've already filled the 1TB internal drive, it's not much of a worry, at this point. If you fill the internal drive with photos, downloads, etc, etc., then you may run into a problem down the line.

 

[KevKaos]

I seem to recall that Apple recommends a hard drive used for a Time Machine backup be at least 2x the size of the drive you are backing up.

But, unless you've already filled the 1TB internal drive, it's not much of a worry, at this point. If you fill the internal drive with photos, downloads, etc, etc., then you may run into a problem down the line.

I just got the iMac, so there isn't much on it at this point. I guess I will just go ahead and use it and then shop around for 2TB drive as the prices continue to come down. Thanks for the speedy response.

 

[MacDawg]

Personally, I have a 500 GB internal drive with only about 150 GB used
I use TM on a 500 GB partition on an external drive and have had no issues

I think you will find it relates more to the amount of data and changes you have than to the actual physical size of your iMac HDD

1 TB, if used solely for TM will no doubt serve you well for a long time

 

[witness]

1TB Time machine drive should be reasonable. You can always upgrade later when you need the space (and when drives are cheaper).

You can also setup exclusions in Time Machine, so if you have some large files that do not require backup you can add them to the exclusion list.

 

[JNB]

A TM volume of 1.5-2X the main drive's capacity is nice; remember the capacity should still be well in excess of the actual space used, so you're good. If you decide to get a larger drive for TM, the residual 1TB drive could be used for cloning (SuperDuper! or CarbonCopyCloner), which is also recommended as part of a robust backup plan. TM gives look-back, cloning gives you an "aw, damn!" bootable recovery in the event the iMac's internal drive goes TU.

 

[KevKaos]

Personally, I have a 500 GB internal drive with only about 150 GB used
I use TM on a 500 GB partition on an external drive and have had no issues

I think you will find it relates more to the amount of data and changes you have than to the actual physical size of your iMac HDD

1 TB, if used solely for TM will no doubt serve you well for a long time

Ok, that makes sense. Good news as well. I need to buy my Applecare yet, and I would like to go up to 8GB memory at some point.

JNB: I'll keep your input in mind. That sounds like a great plan.

 

[MacDawg]

TM gives look-back, cloning gives you an "aw, damn!" bootable recovery in the event the iMac's internal drive goes TU.

Exactly... and we have always agreed on this JNB

CCC = "aw, damn... my HDD just crashed and I need to keep working"
TM = "aw, crap... I deleted that project last week/month"

I do both consistently, and as of today, I will do them on separate drives 🙂
The other consideration is having an off site backup in case of real disaster/theft of everything