Hardware supported?

[Fluffles]

MeX wrote:
> On Mon, 2007-Feb-26 at 00:56:59 +0100, Fluffles wrote:
>   
>> Onboard RAID does not really exist. The actual RAID is done by drivers;
>> onboard RAID is actually software RAID with a minor RAID BIOS which can
>> write metainformation about the array configuration and has BIOS
>> bootstrap support. This is also called "fake RAID". FreeBSD does support
>> some fake RAID metainformation though, by reading the metainfo from the
>> disks and assigning it's own software RAID-mechanism to it. For
>> information of which metainformation formats are supported, checkout the
>> ataraid(4) manpage:
>> http://www.freebsd.org/cgi/man.cgi?query=ataraid&apropos=0&sektion=4&manpath=FreeBSD+6.2-RELEASE&format=html
>>
>> If your fakeraid is called "Intel MatrixRAID", then yes FreeBSD does
>> detect the metainfo and you will have a "ar0" for your first fakeraid
>> array. You should be able to install (and boot) from fakeRAID since
>> there is BIOS bootstrap support.
>>     
>
> What does mean that ataraid driver can NOT write metadata format? I use
> NVIDIA MediaShield on SUN X2100 M2 and it seems that all works:
>   

This means you cannot define ("create") an array; this you should do in
the RAID BIOS setup instead. Metadata read still means it can read and
write to the array. This is all stated in the manpage, by the way:

     Read-only support for a metadata format means that FreeBSD can use the
     given RAID array for normal read/write operations.  Creation and
rebuild
     of such arrays has to be done from the controller BIOS.

     Read and write support for a metadata format means that FreeBSD can use
     the given RAID array for normal read/write operations. 
Additionally, the
     atacontrol(8) utility can be used to create, rebuild, update and fail
     such RAID arrays.

- Veronica