[mythtv-users] OT: Raid Server troubleshooting

[Brian Wood]

Joe Ripley wrote:
> On 10/11/07, Nathan A. Smith <nasa01 at comcast.net> wrote:
>>> I don't know... AFAICT it might be, since I cannot find *any* reference to
>>> an onboard processor, and even some remarks that these cards are ill
>>> suited for low power machines...
>>>
>>> But I really cannot tell with certainty... The fact you use ATARAID seems
>>> to suggest it though!
>> Just to show my ignorance...
>>
>> How did you tell they are using ATARAID?
> 
> As mentioned, a hardware RAID card has an onboard CPU and onboard
> memory that does all of the grunt work of computing the RAID
> calculations.  "Fake" RAID systems have the CPU do the work and just
> supply an interface/BIOS to the computer.
> 
> As Brian mentioned, price will usually tell the difference quickly.
> If your RAID card cost around $100 - $150 it's most likely "fake
> RAID".  If it was more like $400 -> $1000, then you probably have a
> hardware RAID card.
> 

A real RAID card will usually have some RAM on it, often using standard
SIMM sockets. The RAM is sometimes optional and/or expandable.

Usually a battery to maintain the RAM if power fails is included.

Some sort of fairly beefy processor will be on the board.

An extensive setup and diagnostic program will be part of the card's
firmware.

But cost is still the best guide. You get what you pay for.

In truth all RAID is "software" on some level. So-called software RAID
runs on your main CPU while hardware RAID offloads the tasks to a
separate card where the software is run independently of the main CPU.

beww


beww