[apollo11]

Apologies for this technically poor description.

I replaced the Superdrive in my 15 inch Core 2 duo MBP with a 1 Tb drive.

I use Superduper to automatically duplicate the boot drive to a partition on the 1 Tb drive once daily.

Is there a mechanism which will duplicate the boot drive on the fly, continuously?

Thank you for your help.

[P]

Yes, it's called RAID1, and it's not really a good backup system. The only thing it is good for is if you need 100% reliability with no downtime. If it's backups you're after, use Time Machine. Cloning like you do is very good against hard drive failure, but it's useless if you have a file corruption that you don't notice directly.

[apollo11]

Thank you,
My MBP core 2 duo backs up to TimeMachine over Airport too but it is always doing it!

The 1st TimeMachine Back up was done via ethernet but since then it is over Airport. It may have just backed up say 8 Gb then the next back up is 25 Gb then it may do some < 1Gb back ups then again a 32 Gb back up that takes all day, tying me to my Airport.

I cannot fathom why this is so. Raid1 may give me some temporary independence. How do I implement it ? I have seen it on Disk utility.

My 2 HDD , iPod , iPhone, iPad, sons' iPhone, wife's iPhone and 2 off site portable drives back up 9000 pictures and some video of my late daughter who died last year aged 17 of cancer. This is my reason for this post. Thank you again

[reader50]

In your Time Machine settings, is it possible you're backing up the 1 TB backup drive too? That could explain sudden big backups on some days. SuperDuper does it's thing, then Time Machine saves the fresh backup.

[apollo11]

Thank you again, there are no indications present that the 2nd partition of the 1Tb drive is being backed up in Timemachine.There are files exclusively on that partition and they are not on the time machine. As far as I am aware only the booted drive is offered for back up.