Have a V440 server which we need to connect up to a SE6140. Did the zoning on the 3900 brocade silkworm and did mapping from the array to the host manually host initiator did not autodetect the wwn and had to key in manually. probe-scsi-all cannot show the fc disks. What is the problem here?

latest fw on all devices? if the wwn is not autodetected it is in most cases a san/zoning problem...

I don't know how to relate this. Client was using his own CAM. not sure of the version. will CAM ver play a part too? So how to solve the basic issue here, which is, the OBP not detecting the SAN disks..?

the fw for the 6140 comes with the cam software... if it's a new setup try to use the latest version (6.5.0?) and update all devices. also check the fc hba's in your v440 for latest fw and update the brocade.
but all this is meaningless if the configuration of the zoneing is wrong. the host won't see the lun's. but this is config work and i can not help with this remotely. you have to check the ports both logical and physical for correct config.

did something to isolate the problem. did direct connect from host to storage and the LUNS can be presented. No problem.
So the culprit is the switch end. Any ideas how we can force the brocade silkworm 3900 to see the SAN?

yes, using the right configuration is the only way.

Just to update, managed to get it working after enabling the config from the CLI. something did not make it work from the WebGUI