I have no opinion nor real experience to add, but what about the
Domino running in the primary with the backup servers running in a
separate LPAR? I offer some comments inline after each disadvantage noted.
Neil Palmer wrote:
What is the general consensus on whether or not you need (or should)
run Domino (for email & Sametime) in a separate LPAR? I can't really
think of a lot of advantages, just disadvantages like:
- more maintenance on the LPAR for release upgrades, PTF's, etc.
Actually the maintenance for the primary is one good reason to have
the servers on an LPAR. That is, the maintenance on the primary does
not impact the Domino Servers which can remain active on their own
partition. This is ideal where availability of the Domino supported
activity is critical, even if only for its providing the interface to
document why and for how long the primary partition is not available.
Additionally when maintenance is done on the Domino LPAR, that could
be limited to just HIPers and Domino Groups, to limit its downtime more
than for a partition providing all functions. Then additionally having
the backup and primary Domino servers on different partitions allows the
separation, saving from harmful changes by maintenance affecting all
servers. Not only does maintenance on DomSrv1 allow falling back on
DomBck1 during the maintenance, but if the maintenance should happen to
leave the server failed, the issues for recovery are less drastic [i.e.
find the fix to add, versus the removal of the maintenance] and possibly
less urgent because the backup servers are still active where the
problem was not introduced.
- a more expensive system because of the LPAR driving requirements
for additional disk controllers and disk, driving a requirement for
an otherwise unneeded expansion unit, etc.
The other copy of the OS can be cheaper; the i5/OS Application Server
[Edition?]. A modified configuration can improve system performance and
increase options for even further variations and/or refinements in the
configuration. An important consideration is if the Domino server(s)
may give rise to a requirement for more disk space, such that the
boundary for expansion may be hit sooner and with more impact, to the
one primary partition configuration, than if planned separately from the
beginning with a secondary partition.
- more PC server like in that you end up with unused processor and
disk resources that would be better utilized if Domino was running in
the main system/partition.
The system is fairly efficient at sharing CPU, and configuration
options on how to share. Is it better to add disk [and optionally
balance] to the one primary partition, or to each partition as required?
I can't think of any cases where errors in Domino would cause a
production system/partition to crash - but has anyone experienced
The Subsystem gives partitioning within the main system/partition,
and given the subsystem can end, then all should be well. For this
reason, indeed there is a lesser need to have a fully separate LPAR or
physical server as one might expect with other operating systems.