SCSI Ultra160 PCI 64-bit controller cards

[COTLG]

In setting up an Oracle Real application cluster:

1. Can one have two up two SCSI Ultra160 PCI 64-bit controller cards run one 36.7GB 10000RPM ATLAS 10KIII SCSI 68 PIN Ultra 320 HARD DRIVE - BULK hard disk drive?

2. What specification of terminators can one use with this configuration?

 

[connollyg]

Chike,

The simple answer is NO!

But the real answer is much more complex.

Firstly its about HBA's that are qualified to work on a shared SCSI bus (aka multi-initiator and/or multi-homed) and most are NOT!

Secondly its all about ownership and synchronisation! If you have a disk on a shared bus (ie two HBA's even if these HBA's on on the same server) what stops updates for the same disk block coming down both paths? especially if they are conflicting updates?

But to give you a better answer we need to know what your config is really like and what you are really trying to achieve by using a shared bus.

If you really want to go ahead with this you might want to consider storage systems that are designed to work in this kind of environment, so look at devices like HP's MSA500 product! (look under the Proliant Server section)

G

 

[connollyg]

Terminators!

Well the recomended way to setup a shared SCSI bus is to:-
1) Remove the terminators from EVERYTHING including HBA's and devices.
2) For each SCSI connector use a "Y" cable
3) Use standard SCSI cables to connect all the "Y" cables together.
4) Put ONE terminator on each end of the bus, ensuring that you have a properly terminted bus with a MAXIMUM of TWO terminators.

The "Y" cables mean that you really do have a SCSI bus and that you can disconnect a device without breaking the bus and causing all kinds of spurious signals upsetting the devices that are still connected!

G