Fedora 9 Boot Problem

[Alan Cox]

> translation...high point is fake raid though I don't want to denigrate
> high point stuff or their attempts to support Linux.

To be honest the software RAID interfaces are usually better than
hardware ones especially once you reach the world of PCI express where
each controller has its own bandwidth to the memory controller.

> Seann has omitted coverage of things such as hot spares, hot swap
> awareness, automatic rebuilding of arrays, battery backed write cache,
> firmware BIOS configuration and certainly many more features of real
> hardware RAID which is why you are hard pressed to find these cards for
> under $600.

md can do autorebuild from scripts, hot spares and if your hardware
supports it (most current SATA does) hot swap. The big one you get from
some of the hardware assisted controllers is the battery backed cache.

When you start looking at generic AHCI SATA controllers and software RAID
you have to spend quite a lot to outperform it materially. It's easier to
get hardware wins in RAID5 but in RAID0/RAID1/RAID1+0 CPU usage is pretty
low and extra CPU power is cheap.

Alan