[CentOS] Intel RAID controller

Bryan J. Smith b.j.smith at ieee.org
Thu Sep 8 20:42:34 UTC 2005

"Bryan J. Smith" <b.j.smith at ieee.org> wrote:
> Lastly, I've also not seen FRAID-5 supported yet either.

FYI, from the kernel 2.4 iswraid README:  

   While they may or may not be distinguishing features,
   iswraid also:
   * supports RAID0 (striping) over n-disk volumes;
   * supports RAID1E (mirroring with striping) over n-disk
   volumes---this is equivalent to RAID1 for 2-disk volumes
   and to RAID10 for 4-disk volumes;
   * supports multiple volumes per array ("Matrix RAID");

Again, no newer FRAID-5 support.  I'd actually like to see
how well Windows FRAID-5 works against software RAID-5 in

  * deals with missing disks in a reasonable manner;

This one is my favorite.  ;->

In other words, the fact that you have no intelligence local
to the hardware is a major issue, one that software can't
solve.  I.e., you can't just hot-swap FRAID hardware, let
alone if a device goes down, the kernel might panic.

Why?  Because the "raw" individual drives are still what the
kernel communicates with.

  * can operate with volumes in degraded mode (unless
  instructed not to);
  * implements disk error thresholds;
  * tries to satisfy failed RAID1E reads using each failed
  disk's mirror.

Again, more subjective differences that could be an issue
between the FRAID 16-bit BIOS and the OS -- especially when

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