[Beowulf] hardware RAID versus mdadm versus LVM-striping

[Richard Chang]

Joe Landman wrote:
>
> Its a software RAID implementation pretending to be a hardware RAID 
> implementation.  They are rarely if ever as good as MD.  Many of them 
> in Linux will invoke dm (the "other" RAID engine) as dm has "support" 
> for fake-raid.  Note that we have lost data (multiple times) with 
> dm+fake-raid in testing, so we don't recommend its use in important 
> machines (ones which you can't afford to lose).  This could be due to 
> bad drivers for the chips in question, but we aren't taking chances.
>
>
Hello Joe,
I would like to know specifically what models of LSI boxes are software 
RAID implementation pretending to be a hardware RAID implementation. I 
have a few LSI boxes where I work, and your post made me think if they 
really are Hardware RAID implementation.

I have the LSI 2822(old), LSI 4900 & also LSI 7900 controllers based 
storage.

How do we differentiate between the software and hardware RAID 
implementations. ANY visual difference?, are they identifiable?.

Richard.