View Single Post
  #2  
Old September 8th 04, 03:18 AM
NuTCrAcKeR
external usenet poster
 
Posts: n/a
Default


"WS" wrote in message
...
We have an RA4100 with dual RA4000 controllers that, a long time ago, was
set up for redundancy. What I want to do is remove this redundancy, so

that
the second RA4000 controller in the unit operates as a separate path to

the
same logical drives.

What piece of software/hardware controls whether this second controller is
in "redundant mode" or "additional path" mode?

Thanks in advance.


That isnt how redundancy works. Well, that isnt strickly true. You can have
2 HBA's in a system, and have one setup as a failover. You can have 2 RA
controllers in a chassis, and one has to be in standby mode. Through
combining multiple HBA's, multiple FCAL Hubs/Switches, and multiple RA
cabinets with redundant controllers, you can have a reasonably HA system.
But there will always be a momentary pause when the failover happens,
regardless of how much hardware you throw at the problem.

let me guess ... you are trying to build a cluster?

make sure that the firmware on the RA controller is 2.60. this includes the
ability to enable SSP (selective storage presentation) at the controller
level, and will allow more than 1 HBA access to a volume. However, only 1
HBA can access that volume at a time. This is due to the way that NT based
systems work with drive volumes and volume signatures. There is only 1 OS
platform that can have multiple systems accessing the same physical
filesystem at the same time. Only 1. And its a VAX. For 20 years, its what
every other platform has tried to be.

As for your question about dual path and all that ... what OS and version
are you running? NT4 ? 2000? 2003 ? Linux?

If I am wrong, tell me what you are trying to do and i will see what I can
do to help.

Ciao,

- LC