RAID 1 and Carbon Copy Cloner

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Level 1

126 points

RAID 1 and Carbon Copy Cloner

I am trying to clone (using CCC v2.3) the contents of a hard drive that has Mac OS X Server 10.3.8 on it to a RAID 1 array so that we can use the RAID 1 Mirrored array as the boot drive. The clone completes successfully but when I try to boot from the RAID volume I get as far as the gray apple and the spinning gear and then I get the symbol of the circle with the line through it. Computer is a PM G4 1 Ghz DP Mirrored Door with 512 MB ram. The 2 drives for the RAID 1 array are two identical 80GB Maxtors set to cable select. I can create a single drive clone from the original drive no problem. Any suggestions? Thanks.

Posted on Sep 23, 2005 2:55 PM

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Answer 1

UptimeJeff

Level 4

3,479 points

Sep 25, 2005 7:51 AM in response to Polarbear

I don't have an answer to the original question...

But I can say for sure that you can copy a non-mirror to a mirrored set with CCC.
CCC is just a series of scripts that copies data (using ditto) from one volume to another. It's just copying data, it's not modifying partitions.

I don't have an answer as to why it's not working for you. It should.
And considering you can successfully clone to a single drive which boots, I won't get into the basics of CCC (like the Bootable checkbox).

Jeff

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Answer 2

Polarbear

Level 1

145 points

Sep 24, 2005 8:44 AM in response to Dr_Raven

This wont work for obvious reasons. The clone you have is just that, a clone. When you roll out a clone that is supposed to run on a single master disk and try to boot it up using a RAID it will fail. If you had a hardware RAID it might work but not since all the info about the RAID is software based and your clone has no whatsoever clue that it all of a sudden resides on a RAID, right?

Have a look at SoftRAID, it handles merging disks.

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Answer 3

Dr_Raven Author

Level 1

126 points

Sep 24, 2005 9:47 AM in response to Polarbear

Hey PolarBear, thanks for the response.

Actually it still doesn't seem that obvious to me so I need a little more help here 🙂 I am using a RAID array that is mirrored, and I always thought a mirrored array is supposed to act and look like a single volume. So other than residing on two disks, what is it about a single RAID 1 volume that makes it appear differently than a single hard drive to a program like CCC? And why would a HW mirrored RAID work when a software RAID won't? Lastly, prior to posting this I scoured the Apple Discussions for info on RAID and CCC and several people have indicated they are able to use CCC to clone from a single HD to a Striped array. Why would this work and a Mirrored array would not? I appreciate your time in responding to this. Thanks!

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Answer 4

Polarbear

Level 1

145 points

Sep 24, 2005 1:44 PM in response to Dr_Raven

CCC makes a carbon clone of the whole system, right? Your system (made with Disk Utility) has told the OS to emulate a mirrored RAID using your two disk, right? So when you roll it back and you have a totally different drive setup how will the clone know how to deal with it? If it were hardware it would not have to interact with the system to tell it what kind of drive setup you want to use since it´s all handled by the ROM on the RAID-card.

If you use the software solution the drive settings will "tag along" inside the clone since all the preferences for what kind of drive setup you were using is handled by the OS when using a software based RAID.

A striped array is a whole different thing, the only thing it does is split data between the two drives to improve read and write speeds. It will probably work (i say probably but i would surely not recommend it) because a striped array does not have to be in sync, the two drives can look totally different (even if they act as one in the finder) and it will still work. But the preformance gain of the clone will be almost none.

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Answer 5

Polarbear

Level 1

145 points

Sep 25, 2005 8:01 AM in response to UptimeJeff

Good luck. Woooly thinking here, he is using a software RAID and where is the setting stored for the software RAID? In the OS of course (wich he copied over tho the new drive), the partitions is software based if that´s news for you.

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