Kernel Panic when making RAID 1 with data block size of 256k?
 

Hi,

I've had multiple problems with making RAID 1 sets from 2 7200 rpm drives in a RAID tower, connected via eSata and Expresscard slot to my Macbook Pro.

I've read that the bigger the data block size you choose, the better it was, especially for video. I was going to capture Prores so to be sure, I tried the 256k option.

When creating the RAID 1 set, it gave a Kernel Panic. I could easily recreate this problem on different Macs (Mac Pro, Macbook Pro's) and different drives.
Afterwards the discs became unreadable, and sometimes other drives in the RAID tower too (I could get the information back with Data Resque, so no worries).

After I got the Kernel Panic, the Mac would get the Kernel Panic everytime while restarting.
The solution was to connect the RAID tower via USB 2. Then I could read the disc again in Disc Utility to reformat.
In the beginning I didn't know where the problem lied, but then I noticed when making the RAID 1 with the default 32k, there was no problem.

Luckily 32k was enough to edit and capture Prores, but does anyone know why different Mac's all crash on creating a RAID 1 with 256k block size? I'm curious to know, and avoid it in the future. (I didn't try other options in between, because I didn't have the time)

Best regards,

OS version?

10.5.8 for my Macbook Pro.
Some of the others I tried ran Leopard too, but I don't know which point-version.

This sounds like a driver issue, check the manufacturer of the Expresscard to make sure you have the most up-to-date drivers. For example, Seritek has issued newer firmware for their cards to address this specific issue.

Also, your raid tower controller chipset might be the culprit. Check the drivers for that as well if they offer any.

Are you using Disk Utility to create a software RAID or is it hardware based in the tower? There too could be another snag.

Try setting up RAID-0 rather than RAID-1; if "0" works but not "1" it most certainly has to be a communication error somewhere between EC34 card and/or tower.

Many people use Softraid instead of the apple utility. But be cautious with Softraid if going to 10.6 soon.

Sounds like something is broken in your tower. The port multiplier is the major hardware piece on most external arrays. But you have USB so I'm not sure what you have.

For expresscard eSATA the Pro Sonnet is the fastest card. Probably 3x USB.

Thanks for all the replies!

Hi Don,

the problem was on Leopard in my case. The blog does seem an interesting reason to try out SoftRaid...
Thanks!