SuperDuper hard drive swap

ChemiosMurphy said:

Hi everyone.

Here's my problem. I have a Raid 0 (two WD6400AAKS) that needs backing up. All four of my internal bays are filled, boot drive and a clone of the boot drive plus the 2 640's in RAID-0.

Obviously I need to back the Raid-0 up. I want to do it externally with an OWC Elite Pro case with the exact same drives and just use Super Duper! to clone to internal Raid set.

I also want to be able to take the Raid array with me to school, so here's my questions.

-1. Once the external RAID is a clone of the interior one, can I take the external array and use it on another computer, and come back and use Super Duper's "Smart Update" to get the internal drive to the exact state of the external one?

-2. Is this a dumb way of doing it? I'm screwed because the files are like .88 GB a second, and there is a lot of footage...

Thanks!

Click to expand...

Just want to throw in a couple of thoughts to this- because yes you certainly do need to get that RAID 0 backed up since that RAID type does not use error checking and any write error can destroy all the data on the drives!

Based on that, I am not sure why you would want to use an external RAID to back up the internal RAID. I personally would not want to introduce the non-error checking in my backup too. I see no reason to use anything but a single 640Gb external drive and SuperDuper or Carbon Copy Cloner for backup. Even better if you are convinced you want to use two drives for your backup, put each in a separate case and backup to each one of them as a separate backup, yielding two backup copies of your data to be EXTRA confident! Personally I do that on my most important data drives and rotate them as the current backup.

Anyhow, in answer to your specific questions:

1. Yes, you could do that.
2. Well, you are quoting the equivalent of 880 Mb/S so I am not sure where that number is coming from, so some additional detail could help out here! Since your description seems to indicate that you have a Mac Pro, you have FireWire 800, so an external enclosure with a FW800 interface will provide some nice backup speed. Also remember that the only time it will take a really large amount of time is during the initial backup. After that you will just be doing incremental backups, so the time factor will plummet. For the first part of the question, see my first paragraph!

Good luck with it all- just get it backed up and keep the backup current and all will be well!

Work off the fw800 external raid, backup to your internal. Then you can take the raid drive anywhere and use it.

Get the OWC enclosure that does the hardware raid. I wouldn't recommend trying to just use OSX to do this. Get a Raid0 external that has a controller built it and you're set.

OK- that description does help a bunch!

First off, I would tend to agree with Sean Dempsey above- I would use the dual drive hardware RAID case from OWC too. I have one and it is a nice chunk of aluminum, would make the transport easier and I think you would be much better suited with the hardware RAID as well. You can see the enclosure in question at http://eshop.macsales.com/item/Other World Computing/MEFW924AL2K/

Now the downside to that obviously is that it does not have eSATA ports (only FW800) so some degree of transfer speed would be lost but you might be surprised overall with the transfer speed of a hardware RAID over FW800. Now the upside to that plan is that you do not have to figure in the cost of a SATA PCI-e card so the hookup to the home system and the university system would be consistent...

Now as far as SuperDuper incremental mode, yes I trust it completely and use it for backing up about 3Tb of drives that I use- and have been for quite some time with no problems at all. Of course as soon as I say that, your first experience will be trouble, right?

The only thing I want to add (and even though you did not ask about this! LOL) since I am a fanatic about this is I would question using an internal drive bay to backup an internal drive as you have noted that you are doing with your boot drive. The logic here is twofold if both the original and backup drives are being powered by the same power supply:

• 1- If there is a problem with the Mac Pro power supply that happens to spike one drive it will probably spike both, potentially rendering them both damaged beyond repair- thus leaving you with zero data. Because of that, all my internal drive backups are done to external drives. Now granted the chances of that kind of problem may be slim, but ...
and...
• 2- Since a backup drive only needs to be powered while actively backing up (when using programs to backup other than Time Machine), I power my backups down to reduce physical wear time on them when not in use. That is impossible when used internally unless you want to physically remove it- which the drive bays make fairly easy of course. Before I had a good uninteruptible power supply I also used to physically unplug them when not in use to isolate them for insurance since we have notoriously lousy & spiky power (lots of thunderstorms, etc) in my area.

One important addition I just noticed I missed- when you said:

"So when i'm at Drexel with teh two individual drives, I can just plug each drive into a FW800 port and voila! hopefully the array will work... will it?"

Unless you are always on the same computer there during every session of use (and you set up the Apple Software RAID for the two specific drives before any data is loaded on them) then no, the method you described will not function as you describe. Since you are talking about two cases, hence no hardware RAID as is provided in the OWC case, if you needed to use a different system at the university (which would not know about your software RAID) you will be out in the cold. I am about 99.7% positive that you can't set up a new Apple Software RAID with drives that already have data striped on them. Using the OWC case on the other hand would work fine with multiple university systems- just plug in one FW 800 cable on any one and you are off to the races. Any of the systems with a FW 800 port will see the enclosure as a RAID since that is handled by the enclosure's hardware.

Hope that is not all too confusing and lends a hand!