HostRaid support on FreeBSD

[Scott Long]

Maxim Sobolev wrote:
> Dag-Erling Smørgrav wrote:
> 
>> Maxim Sobolev <sobomax at portaone.com> writes:
>>
>>> Well, my knowelege about internals of software RAID controllers is
>>> quite limited, but as long as I know they are no more than BIOS with
>>> UI for setting up RAIDs and interface to main BIOS that hides internal
>>> RAID structure allowing to boot off the RAID. Also they provide some
>>> persistent storage for RAID configuration, I assume either in some
>>> controller's NVRAM or on the HDDs.
>>
>>
>>
>> The configuration is always stored on-disk, otherwise it wouldn't be
>> possible to recover from controller failure.
>>
>>
>>> Therefore, the same set of GEOM
>>> RAID modules can work with different software RAID controllers (SCSI,
>>> ATA, SATA etc) if there will be a standard way to extract this info
>>> from the controller's driver, and present it in some common
>>> format. That's what I am talking about.
>>
>>
>>
>> You're kicking down open doors.  This problem has already been solved
>> for Vinum, which is conceptually identical from a GEOM point of view.
> 
> 
> Nah. As I said there should be some standard way to extract RAID 
> configuration info out of controller's driver in controller-independent 
> format.
> 
> -Maxim
> 

Correct, and vinum lacks this.  My goal with RAIDframe was to provide
this, but I had to abandon it due to lack of time.

Scott