Mirrored RAID: MediaKit reports block size error

Question

Level 1

106 points

Mirrored RAID: MediaKit reports block size error

I am trying to create a 2nd set up backup drives for my photos. I have two new iomega 2TB drives, which look essentially identical to drives I'm currently using as my primary backups as a mirrored RAID set.

I can start the process with freshly erased and reformatted drives (with the default mac format, extended, journaled, unencrypted, not case-sensitive). And after a minute or three, I see

"MediaKit reports block size error, usually caused by not being a multiple of 512."

The RAID options are Mirrored RAID, Mac extended journaled, and options settings are default.

I see several series of posts with complaints about encrypting RAIDs and disk block sizes, but not unencrypted errors. I actually started out trying to do this with the 2006 MBP running 10.6.8 and got a different error: "POSIX reports: the operation couldn't be completed. Operation not permitted." I wasn't sure whether the 2TB RAID I already have was set up iwth the older or newer computer--it was definitely before I put Lion on this one--so I tried this one and now have a different error.

Any idea what the problem might be?

Mac OS X (10.7.4)

Posted on Aug 18, 2012 2:13 PM

Reply

Answer 1

Donot Haveone Author

Level 1

106 points

Aug 18, 2012 4:30 PM in response to Donot Haveone

Update: I spent some time on the phone with an Apple support RAID expert, and couldn't figure out what the error was; we couldn't bypass it by playing with partitions on the drives, or any of another couple of manuevers that I've already forgotten. He noted that his own searches were showing a lot of mentions of similar problems but only with Iomega drives, and he was finding the same links I found earlier about problems creating encrypted drives. Now trying to decide if it's worth throwing more good money after bad for a call with Iomega support, and waiting to see if the iomega forum is at all helpful.

Reply

Answer 2

Donot Haveone Author

Level 1

106 points

Aug 22, 2012 12:19 PM in response to Donot Haveone

I finally got to 'chat' with an iomega representative, and he said that the new Iomega MiniMax drives use 4k sector sizes, not 512, so that probably is exactly the incompatibility.

I will look for alternative drives to see if they have compatible sector sizes.

Reply

Answer 3

Donot Haveone Author

Level 1

106 points

Aug 25, 2012 6:25 PM in response to Donot Haveone

BTW, in case anyone has followed this who had a similar problem, today I purchased two Western Digital My Book Studio 3TB drives, and there was no problem making them into a RAID set.

I have successfully avoided having to learn about eSATA and such for a while longer, while still keeping up a little more robust backup than the minimum necessary. Whew.

Reply