Re: mptsas and mptbase sas problems on fujitsu-siemens rx200-s3 rack server

[Eero Volotinen <eero.volotinen@iki.fi>]

> The first thing to note is that HBA based hardware RAID is not something
> anyone should enable blindly.  The fusion isn't even a dedicated RAID
> card, so its RAID engine is effectively jammed into left over firmware
> space because it was available (HP, for instance, required this
> capability to be removed on some of the HP OEM models).
> 
> Even for dedicated hardware RAID, the problem you have is that it
> effectively puts the onboard processor in the direct I/O path.  Since
> cards are (reasonably) cheap, these processors don't have the fastest
> busses or highest processing capabilities, and often top out at
> surprisingly low bandwidths, especially for compute intensive
> transactions like RAID-5/RAID-6.

Mainly this internal sas array (2*73GB 10k sas disks) is used for 
operating system only. Currently I am running it on raid1

After weekend I can try to run it without hardware acceleration,
it mainly makes installing operating system a bit harder.

So, this looks like that I need to buy working sas raid controller,
if I want to use hardware raid on this machine? Rest of data is on
fibrechannel san and it is working fine.

--
Eero