Rick wrote:
At 04:06 AM 3/18/98 GMT, David A. Lethe wrote:
>On Tue, 17 Mar 1998 10:41:51 -0500, Rick Tomlinson <[log in to unmask]>
>wrote:
>
>>Has anyone ever used or heard of anyone using mirrored EMC Symmetrix
>>drives for the system volume set?  What other alternatives are there for
>>adding this type of redundancy?
>>
>>
>>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>Rick Tomlinson       [log in to unmask]      (336) 758-5811
>>Information Systems                 fax        (336) 758-7127
>>Wake Forest University             www.wfu.edu/~rick
>>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

And then David wrote:

>Look at IBM's SSA for the HP3000.  It is typically several HUNDRED
>PERCENT faster, at about half the price.  Hardware mirroring is in
>beta now. All the usual features you would expect, including:
> - hotswap
> - multiple initator support (with limitations)
> - RAID capability
> - Works with HP's predictive & other diagnostics
> - priced around 50 cents/MB.
> - very high density .. almost a terabyte in a HP 19" rack
> - no single point of failure (redundant paths, cables, power)
> - add, delete, reconfigure, mount them to different systems without a
>reboot!!! (requries 5.5)
>  yada yada yada
>
>I know, I was the project leader  on the team that ported it to the
>HP3K I contracted Michael Hensely with Allegro to port the diagnostic
>routine to MPE/iX ... So you know it was done right!
>

Just a couple of comments.  First, in direct answer to Rick's question, you
can use EMC Symmetrix drives for the system volume set but only in a RAID 1
configuration.  Works great.

Second, a little caution is in order before making the jump to SSA for
production.  I'm sure that David's company did a great job in bringing the
technology to the 3000.  My concern is that it is not "officially"
supported by HP.  Until HP gets on the bandwagon of SSA on the 3000, I will
find it very difficult to recommend it in the 3000 environment.  At the
very least, David's company should get HP to say SSA does no harm and is at
least as robust as JBOD (Just a Bunch Of Disk).

Lastly, just because Allegro ported the diagnostic routine doesn't
necessarily mean that 1) SSA was "done right" on MPE/iX and 2) that Allegro
endorses the technology for the 3000.

There are other options for this type of redundancy:

  1.  Disk arrays for the system volume set
  2.  Mirrored Disk/iX for all production volume sets
  3.  Quest Netbase/SharePlex for full system redundancy

(pick any or all of the above)

BTW, Interex have recently formed a new High Availability Forum which will
address high availability issues across all HP product lines.  Isaac Blake
and myself are co-chairing the Executive Committee for this Forum.  We
invite you all to give us some feedback on what high availability issues
are important to you and look forward to representing you to HP.  We will
be having several meetings this year to begin the process of advocacy in
the high availability arena so look upon this time as ripe opportunity to
get your requests known to HP in a fully supported way.

Bill Lancaster
[log in to unmask]