Hello All,

   It should also be remembered that parity protection does not supply the
   same protection that mirroring does.  Parity protection supplies the
   ability to rebuild the data in the case of a mech failure.  It does not
   cover disc controller, cable, interface card or power supply (if mirroring
   is set up correctly on separate channels).  Each application will have it's
   own needs for data protection which will dictate whether you spend for
   mirroring or parity protection or no protection.

   In a shop with about 130 HP3000 systems, we have elected to use mirroring
   for all class A and class B systems (critical and kind-a critical) user
   volume sets.  As a result, we rarely have any downtime associated with disc
   failures at all.

   We would, however, very much like to see both mirroring and parity
   protection for system domain.  There are a number of variables which effect
   the choice such as applicaton criticality, available monies, backplane
   space, floor space, backup needs, etc.

   Regards,
   Carl Sitherwood
   HP Atlanta

   < Appropriate verbage regarding opinions expressed .... >

______________________________ Reply Separator _________________________________
Subject: Re: Mirroring System Volume
Author:  Non-HP-bill ([log in to unmask]) at HP-USA,mimegw1
Date:    3/25/97 7:53 AM


>
>> Scott McClellan wrote (without identifying himself):
>>
>> > The project to support mirroring the system volumeset is being
>> > considered but is *NOT* committed or fully funded at this date.
>>
<Snip>
>>
>

Richard Gambrell wrote (clearly identifying himself :-) )

>High availability arrays are a real and available now solution. Cheaper,
>too (since you don't need double the spindles), assuming your buying new
>discs, of course. I'd rather HP put effort into work that didn't
>duplicate available functionality. Your needs may vary.
>Richard Gambrell
>

I would much rather that HP commit to, and fund, the project to be able
to mirror the system volume set, given the performance ramifications
of arrays, as well as the cost.

Thanks for listening, HP.

Bill Lancaster