Time Machine Backups

I am considering an external hard drive to back up my files from my new iMac. The book I bought, OSX Yosemite the missing manual, discusses Time Machine as a great way to back up to a drive like this.

It sounds great but I would like to hear any comments on pros and cons of this method.

My hard drive is 1 TB. Do you need a larger external drive to allow for the multiple backup copies?

Any thoughts would be appreciated.

Regards,
Bill

I use TM with TimeMachineEditor to make a backup at noon and midnight only to one external drive. Then I have Carbon Copy Cloner to make a clone of my boot drive to a separate drive. That way if/when my internal boot drive fails, I can boot from the external clone and recover. The TM backup is more for recovery of older files that I may need to recover for any reason, and as a secondary disaster backup. I don't use CCC for that archiving, just cloning.

IN general, your TM backup drive should be twice the size of the files you want to back up. So if you think you'll fill that 1TB drive, you should have a 2TB backup drive. However, if all you have on that drive is 300GB, for example, then a 1TB will be good enough. The clone just needs to be the same size as you currently expect to use, so for 300GB at 500GB backup will be ok.

Amen to all that ferrarr and macinwin said.

My personal experience with Time Machine is checkered: the few times I needed it, it came through as advertised. Over the years, though, I've had issues with backups getting corrupt and having to be rebuilt, etc. which is what drove me to other solutions for a while. I only recently began using it again because I had a spare drive to connect to my Airport Extreme.

For true backup, I use SuperDuper to replicate my rMBP's internal drive to an external, bootable disk. I refresh that image about every other week, so I always have a full image to fall back on in the event of a catastrophe.

I keep most of my user documents on Dropbox, so not only are they consistently held in sync in the cloud, they are also accessible via all my internet-connected devices.

I also use CrashPlan to keep a full, offsite copy of everything.

This is kind of a belt/suspenders/staplegun/krazy glue approach, but I have witnessed what data loss can mean.

Hope this helps!

Thank you for all your replies. I am still pondering what to do and will visit the Apple Store today and talk about this some more.

Regards,
Bill