> Is Raid mirroring on the Adaptec ATA-Raid 2400 supported on 
> the hardware level, or is it similar to software mirroring 
> using CCD?  I used external SCSI raid systems with 
> independant back-planes that do Raid with multiple disks at 
> the hardware level and yet appear as a single SCSI drive to a 
> SCSI controller.  Is there anything similar for ATA (IDE) drives?

http://www.arcoide.com/products/raidcontrollers/raidcontrollers.html

Used a "duplidisk" a while back (~6 years ago) for an OS/software package
which didn't support any RAID solutions.  Later on, we loaded unix on the
machine, and it worked just fine.

> Also, on a side note, does anyone know of any hardware 
> encryption system that encrypts/decrypts at the disk block 
> level with a single common symmetric cipher key (like a 
> triple-DES key generated from a hash of a passphrase)?  That 
> way, one can use that to encrypt a harddisk, and yet still be 
> able to run any filesystem on it, and even the swap & 
> partition tables would also be encrypted, without any 
> preformance loss.  That seems like something that would be 
> easy to build using an ASIC (Application Specific Integrated 
> Circuit) chip into an IDE or SCSI controller.

I'm sure they exist, but I don't know of any.  Check out cgd, though - it
encrypts beneath the filesystem, so you can run ffs, lfs, swap, etc...  IDK
if it's in 1.6.x, but I'm sure it's in -current.  Under the cgd scheme, I
believe the only thing which won't be encrypted is the i386 partition map.

-Jon