Storage Questions and Answers - July 2006



Q. In the follow scenario what configuration would the most efficient/redundant? 8 node netware cluster with 2 HBA's per node, 6 brocade silkworm 3800's for the SAN, and an IBM Fast T900 as the remote storage unit.

A. I do not know enough about the IBM Fast T900 to answer this question. If the T900 has 16 ports then I would build two redundant Fabrics of 3 switches each. I would attach all servers to one 3800 using one of the HBAs and attach the servers to other 3800 (fabric) using the other HBAs. This will use 8 ports of each 3800. I would then build a mesh fabric by attaching four ports of the first 3800 to a middle tier of 3800's with a cross connection between the redundant fabrics. This would create 8 ISLs - 4 to the middle tier in the same fabric and four to the redundant fabric and utilize all 16 ports in the middle switches. I would do the same thing between the middle switches and those closest to the T900, 4 to the lower switch and four to the redundant fabric. I would then attach each fabric to 8 ports on the T900 - assuming the T900 has 16 ports of FC connectivity.

This is very difficult to describe so picture two stacks of three switches. Each host is attached to 8 port of the top switch in one stack and the storage is attached to 8 ports on the bottom switch of one stack. Do this for each stack of switches. Then attach 4 ISLs between each switch in the same stack and 4 ISLs to the other switches in the other stack in an X pattern.

If you need support I suggest contacting Brocade at

Q. Where can a diagram of a SAN properly configured as a redundant arbitrated loop be found?

A. I will attempt to do this without a diagram.

Put two HBAs in your host computers. Get two FC hubs. Attach one HBA to each Hub and then attach each Hub to different Ports on your storage. Each storage subsystem should have two ports that connect to the disk drives using two different loop circuits.

Q. I've lost the UserID and password for a Brocade 3800 SAN switch. I was wondering if there is a way to reset the password to factory default. Any input would be greatly appreciated.

A. I wish I knew a magic trick for this but I don't. You might want to try ADMIN/ADMIN if you have not already done that one or any combination of brocade and admin or the IP address & brocade & admin. Good Luck.

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