[CentOS] Re: hardware raid vs fake raid

Thu Sep 13 16:25:04 UTC 2007
Tom Diehl <tdiehl at rogueind.com>

On Thu, 13 Sep 2007, Mogens Kjaer wrote:

> Tom Diehl wrote:
> ...
>> They do but nothing I can find in there tells me if it is real hardware
>> raid or fake raid.  Adaptec for example, also says that their fake raid 
>> cards
>> are comaptable with Linux but they do not clearly specify if it is fake 
>> raid
>> or true hardware Raid. AFAIK the Adaptec cards are all fake Raid. and some 
>> of
>> ServeRaid cards were also based on the Adaptec chipset and hence Fake Raid.
> My IBM x3500 machines have this card:

This is the exact machine I am talking about.

> # lspci
> ...
> 03:00.0 RAID bus controller: Adaptec AAC-RAID (Rocket) (rev 02)
> ...

Hummmm, Interesting!! Maybe my information about Adaptec is wrong.
> I'm not quite sure if this also has an IBM serveraid name.

According to the specs I have it is branded as ServeRaid 8k SAS.
I do not have the machine yet.

> I don't think it is fakeraid; setting up raid devices can take
> place at bios level, the buildup of the RAID5 or RAID6 volumes
> can run without any drivers loaded.

It does not sound like fake raid. 
> If this is fakeraid I would like a clear definition of the term
> fakeraid.

There is a pretty good explaination of fake
raid here:
And some more info here:

All of it is a bit old but mostly still revelent as far as I can tell.


Tom Diehl		tdiehl at rogueind.com		Spamtrap address mtd123 at rogueind.com