SUMMARY: Dual FC-AL Card for V880

Hi,

finally getting around to writing the summary for the question i posted
last week.  thanks to the following for their help:

	Joon Martin Hansen
	Bob Cummings
	Joe Fletcher
	Chris Price
	Kevin Buterbaugh
	Jody L. Baze
	Tim Chipman
	Larry McCann
	Cribb, Jay
	Jason Grove
	Scott Howard

Some widely varying answers to my questions, but there was basically a
consensus.

1.  almost everyone said the additional card was absolutely necessary
for DMP, naturally.  most also agreed that the card would not provide a
quick and easy performance boost.  it's better to find where the problem
is and fix that, rather than blindly throw hardware at the problem. 
that is, of course, good advice.

only one respondent was also using the same hardware for WebCT, but is
using an external array.  we don't have that much money to spend,
unfortunately.  i should mention that we have been doing some testing on
our E250.  on that system upgrading from solaris 2.7 to solaris 8,
putting in SDS and adjusting maxphys, ufs:ufs_LW and ufs:ufs_HW in
/etc/system, and maxcontig (with tunefs) we've been able to increase
throughput on the e250 filesystem by about 288%.  that's using two
disks, in a mirrored configuration.  using 4 disks in a striped +
mirrored configuration should, presumably, buy us even more improvement.

2. most people said that Veritas was necessary to do dynamic
multi-pathing and to make use of the second FC-AL card.  a couple of
people also mentioned using MPXIO.  that should provide similar
capabilities to Veritas' DMP in VxVM.

3. most agreed that the second backplane was not critical as they are
pretty reliable.  although, one person lost a disk backplane shortly
after getting their V880.

4. and finally, most people said that finding out what the bottleneck
is, was much better than just adding the controller.

thanks for your help!

cheers,		-john
-- 
john benjamins		LTRC - Teaching Infrastructure Support
905-525-9140 x27492	Thode Library B117B


-------- Start original message --------
> Hi,
> 
> we have a V880, dual 900 MHz processors, 4GB RAM running Solaris 8, with
> recommended patches as of Jan. 3.  this is our campus WebCT server and
> we're running WebCT CE 3.7.3.4.  this is running fairly well, except
> that disk throughput is not nearly as good as i'd expect to see. 
> currently we have just the 6 internal 72GB disks that came with the
> system.
> 
> in an effort to increase performance and redundancy, we're looking to
> add an X6727A Dual FC-AL card.  this is at the suggestion of the FAQ at
> http://www.sun.com/servers/entry/880/faqs.html#4.  this FAQ mentions a
> second disk backplane, the dual FC-AL card, cable and the Veritas Volume
> Manager.  due to the high cost, we are not considering the second disk
> backplane, or the Veritas software.
> 
> my questions are:
> 
> 1. can anyone tell me what kind of performance improvement the
> additional card might make?
> 
> 2. what do we lose by not adding the Veritas software?  note that we can
> handle short downtimes if we did have hardware problems.
> 
> 3. also, can we do this without the second disk backplane?  obviously we
> lose the redundancy that offers, but i'm guessing this is a very
> expensive option.  also backplanes should be pretty reliable, right?
> 
> 4. any additional comments or suggestions?
> 
> thanks!         -john
> -- 
> john benjamins          LTRC - Teaching Infrastructure Support
> 905-525-9140 x27492     Thode Library B117B

-------- End original message --------
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