StorageWorks 4354

[Michael]

Archived from groups: comp.sys.hp.hardware (More info?)

We have a StorageWorks 4354 connected to an MSA 1000 to work as our mini-SAN
for one of our environments. We've found ourselves to be storage bound
rather than IO bound and have considered picking up single port I/O modules
to replace our dual port modules.

What I wanted to know is, what else would we be giving up if we were to do
this? I've read about "controller duplexing" with the dual port cards, but I
haven't found any information on what that is besides the fact that it's
part of a fault tolerant setup.

I think I know what I'd gain from moving to a single port module, but it
doesn't seem like anyone does this. What would I lose? What exactly is
controller duplexing?


Michael

 

[Guest]

Archived from groups: comp.sys.hp.hardware (More info?)

"Michael" <michaeln@twentyten.org> wrote in message
news:10ipu5mtm8bsib6@corp.supernews.com...
> We have a StorageWorks 4354 connected to an MSA 1000 to work as our
mini-SAN
> for one of our environments. We've found ourselves to be storage bound
> rather than IO bound and have considered picking up single port I/O
modules
> to replace our dual port modules.
>
> What I wanted to know is, what else would we be giving up if we were to do
> this? I've read about "controller duplexing" with the dual port cards, but
I
> haven't found any information on what that is besides the fact that it's
> part of a fault tolerant setup.
>
> I think I know what I'd gain from moving to a single port module, but it
> doesn't seem like anyone does this. What would I lose? What exactly is
> controller duplexing?
>
>
> Michael
>
>

What the Dual port module does is spitting the backplane into two, if
purchase at single port module all the disk wil be on one SCSI channel.

There are serveral reasons to split the backplane,
1. Two host can share one enclosure
2. For performance when you have 14 WU3 disk on one channel the might be
a performance inprovement if you split the backplane and connect it to
different SCSI channel on your Raid controller.
3. For Fault Tollerance, you can do "Controller duplexing" whitch mean
using 2 controler and mirrors the raid sets betwen the controllers.

Best Regards

Johnny