I am about to replace 2 litghly loaded NW, non-clustered servers (one 6.0
and one 5.1) with 2 new OES:NW servers and cluster them using an ISCSI SA,
probably Adaptec's ISA 1500. It is available in only one hardware
configuration, with 2 Gigabit ports and 4 250GB SATA drives. I am thinking
about mirroring to increase reliability. An alternative would be to buy a
second SAN and just throw it on the shelf unitl it is needed.Note that a
portion of this SAN will be set aside for the future use as overflow space
for an existing Windows 2003 Accounting Department servver.

I can see 3 ways to do mirroring:

1. Use 2 SANs and Adaptec's extra-cost mirroring option.
2. Use 2 SANs and NW's mirroring.
3. Use one SAN and use NW's mirroring to mirror it back to internal
storage, since the servers havve several empty bays available. This could
be done with either one big drive or a software RAID using smaller drives.

I have seen some discussions, though not definitive, about 1 and 2, but
nothing on 3. I am not even sure that 3 is possible.

It would seem that 1 si slowest due to the lack of split reads. 2 would be
faster due to the availability of split reads, but could result in the
interruption of the heartbeat unless compromises to the heartbeat are
made. 3 would be the fastest, assuming it is possible.

Any ideas on which to choose or on the Adaptec SAN? Also, and hints or
pointers to configuration info would also be appreciated.


Wayne Krakau