Bill Lancaster wrote:
>
> At 12:27 PM 1/21/99 -0600, MMRI CS ListServ wrote:
> >We have hardware mirroring (Nike drives) on our 9000 and haven't had a
> >bit of trouble.  We lost one drive and one fan in the last two years and
> >replaced them without any interuption in production.

We have 16 9Gb drives in a Nike 30, no problems in close to a year.
Also
have 12 4Gb drives in Jamaicas, no problems there either.

>>We are planning to eventually convert our primary MPE system with all the
>>Jamaica drives to Unix at some point in the far off future and were warned
>>by our PSS tech that Unix software mirroring is quite a performance hit.
>>(But, he is pretty biased against the 9000's.)
>
> Gee, I like him already :-)

I've heard both ways, it depends on who you ask, and how the HPUX side
is configured.  MPE mirrors by physical drives, just as volume sets
consist of physical drives.  HPUX mirrors by logical volume.  You can
pretty much emulate MPE behavior on HPUX but not vice versa.  You can
also shoot yourself in the foot quite extravagantly on HPUX - you can
mirror a logical volume on the same physical volume (how's that for
brilliance?) and you can also turn off some of the performance enhancing
(but reliability) aspects of mirroring, some of which are quite scary
:-(

Jeff Kell <[log in to unmask]>