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iMacfan · Nov 22, 2006, 06:33 AM

Hello,

As I've now got my Mac Pro up and running, I think that it would be wise to backup - but to do that I need at least a 500Gb HD. However, I'm far more concerned about drive failure than theft, so I'm not sure if I'd be better off with an internal or external drive - any ideas?

David

OreoCookie · Nov 22, 2006, 07:07 AM

An external drive might be a better idea since it is physically separated from your Mac. In case of lightning strike, psu or motherboard failure, an external drive obviously isn't affected as long as it isn't connected to the Mac.

The downside is that external drives are slower than internal drives, although I don't think this will be much of an issue for backups -- in particular for incremental/differential backups.

This has worked very well for me over the past couple of years.

ballzdeep · Nov 22, 2006, 02:21 PM

best to have both options.

have a raid 1 setup for instant backup / redundancy in your system, plus to weekly backups on an external drive that doesn't stay connected. Just attach when doing a backup. Your data will be very safe doing this.

OreoCookie · Nov 22, 2006, 03:59 PM

A RAID 1 is not a backup.

ballzdeep · Nov 22, 2006, 11:14 PM

well raid 1 gives you copies of the data on 2 drives, so if one goes down A: it still runs, and B: you're using your 'backup'. So yes it is a backup, just not a very good one in case of electrical current surge, etc. That why I already posted in my first message if you read it, that a weekly backup (or more if you think it's necessary) is also a good idea for an off computer backup.

OreoCookie · Nov 23, 2006, 01:25 AM

I did and since you have other means of replicating your data, you'll be fine.

However, the reason why I emphasize that a RAID1 is not a backup is the following: it does not protect you against data corruption (e. g. by a bug in an app or a corrupted filesystem) or accidental deletion. You cannot go back to an earlier state of your data. So it's not a backup, but a protection against drive failure (even if one drive fails, you can continue working).

Some people (not you) on this forum think, a RAID1 is a replacement for a real backup -- which it is not. It's a safety measure against drive failure.

ballzdeep · Nov 23, 2006, 09:22 AM

I agree with you there. Some people do use it as their only means of backup, when it is quite poor.

OreoCookie · Nov 23, 2006, 10:15 AM

I just wanted to point that out to the OP, so no offense intended

As a matter of fact, in my experience human error and/or software problems cause more trouble than actual hardware failures.

chris v · Nov 23, 2006, 10:45 AM

If you can afford internal AND external, that gives you the best of both worlds. With an internal backup drive, you've got instant bootability in case of an OS corruption, and repair utilities, such as DiskWarrior, will run much faster from an internal drive than they will from a CD. The same is true for drive failure. However, as people have pointed out, it doesn't protect you from theft, power surges, flood, fire, etc.

What I wish I could afford is TWO external drives for data backup, and a safety-deposit box large enough hold one of them, and swap them monthly. As it is, I take CDs or DVD's off-site, though they're not stored in a fire or theft-proof location, so one can just hope that the odds of my work machine being subject to a power surge on the same day that my hose burns down are pretty remote.