Disk Utility Mirrored RAID Questions

Hi,

I'm hoping the Mac Pro forum is good place to ask these questions. I've set up a 2-drive mirrored RAID in my external FirmTek 4-drive esata enclosure. The RAID was set up with Disk Utility and consists of 2 x 1TB drives.

What I would like to know is how to swap out one of the drives and put in a replacement drive, a step-by-step process (i.e. "eject the raid from the desktop, turn off the power to the external enclosure, swap out drives, turn on power, use disk utility, etc., etc.). I'm not sure if the drives are hotswappable, if I do it all while disk utility is running, or what. My goal is to do this once a month so I always have one spare data copy in case something terrible happened to both drives in the external RAID.

Another question: Will the single drive removed from the pair function just like a stand alone drive if I attach it to another computer? I assume so.

Also, while I've heard that I should be running a separate back-up system as well (I use Time Machine to a 2tb drive), I'm curious whether rebuilding a mirrored raid is more or less time intensive than just doing a drag copy of all the content to another drive. I really don't care which method I use, swapping out a mirror raid spare or just copying to another drive, just would like to know which requires less time and babysitting.

And finally, forgive my ignorance, but if I end up getting a spare swapping system going with the mirrored raid, I assume that the spare with previous data on it gets totally wiped when I put it back in again, that the rebuilding process is "not smart," meaning that even if very little of the data has changed since the last swap out, the whole drive has to be wiped and rewritten from scratch?

Thanks for your help.

Paul

 

Sorry for the delayed reply--just got busy...

Well, maybe I'm using the wrong strategy. You tell me if it is overkill. This is my photo archive, scans and digital files of personal and client data, which I access a few times a week and edit to as well. I don't have it on all of the time, just when I need it. It is very valuable data. I have an offsite backup which is a clone, but wanted to do the safest, affordable data protection while I use it, so that's why I set up a mirror.

My main worry is theft/fire/act of god at my studio, not a hardware failure, though that too I'd like to avoid. My goal is to find an easy system that requires a minimum of fuss. My thoughts were just that once a month or so at the end of the day when I'm done using the raided archive, I could just swap out one of the drives, take that drive home, and when I arrived the next morning, the mirror would be rebuilt and I wouldn't have to do anything else. Of course I could just clone instead, not really that much more hassle, though my spare drive idea, it seems to me is more elegant. Correct me if I'm wrong.

I haven't done an experiment on speed, but I have a hunch that cloning a 1TB drive is much quicker than rebuilding a 1TB RAID mirror drive. If it gets done by the time I come in the next morning, I don't care which method I use.

I love Time Machine, but I already have it running on a 2Tb drive for my day-to-day drives and there is not enough room to handle this photo archive as well. If there was some easy way to have multiple time machine backups going to separate backup drives I'd do it.

 

Speed is always important, but since I'm not accessing these that often and usually only to read data, it's not critical. Safety of the data is the most important thing for me. So I think what I'll do is just keep the mirror and schedule weekly clones via Super Duper to an external disk which I'll store offsite between uses.

Thanks for all your advice, nanofrog.