RE: Load-Src in a Raid5 set

["Andy Nolen-Parkhouse" <aparkhouse@xxxxxxxxx>]

Jeff,

Any single drive which is part of iSeries (or AS/400) RAID protection can
fail and the system will continue to run.  This includes the load-source
drive.  When the drive is replaced, it will be rebuilt.  If two drives
fail in a RAID set and that RAID set is in the system ASP, then the
system will need to be reloaded, regardless of whether the load-source
drive failed or not.

It took a while for the AS/400 to include the load-source drive in a RAID
set.  If you go back to the 400 and 5xx series, the load source drive was
driven by the MFIOP and could be mirrored but not RAIDed.  Beginning with
the 6xx series, the load-source drive could be included in a RAID set.

There may be some knowledge and tales from the pre-6xx days about the
load-source drive failing and the fact that it wasn't included in a RAID
set.  Very true, it could have been mirrored but may not have been.

Regards,
Andy Nolen-Parkhouse

> On Behalf Of Jeff Bull
> Subject: Load-Src in a Raid5 set
> 
> Hi all,
>       I'm on a course at present; the subject came up in general
> discussion, "will an AS400 / iSeries keep running if the load-src disk
> fails
> while it is under RAID-5 protection?".
> 
> The general concensus was that it would continue to run, but would not
> IPL.
> Has anyone been here and have the definitive answer?
> 
> I suspect the answer may be a 'that depends", but I like to know.
> 
> Jeffrey E. Bull