Corrections to these notes

The answer to the prompt "update disk config block" should be Y.
It is also important to fully populate the SCSI definitions - by defining non-existant devices if necessary. However this may have been an artifact of the previous error in these notes which said not to update the disk configuration block.

Introduction

The Instrument computers LPVG and LPVF use a configurable CMD SCSI controller with the ability to multihost and shadow disk drives.

The ex-telescope control computers LPVA and LPVB also used a CMD controller.

These controllers need to be configured at board level by connecting a VT terminal directly to the SCSI controller pcb. If the SCSI controller pcb or a SCSI device is added, removed or changed it may be neccessary to re-configure the board

The following information has been comiled to help in doing this. You should also read the relevant manuel CQD-220/223 SCSI HOST ADAPTER which is a thin white A4 ring binder book. This can be found on the top shelf in the cabinet opposite the WHT computer room door along with the ribbon cable (for connecting a VT terminal to the SCSI controller pcb) .

To configure the board it is neccessary to close down the relevant computers. This means that both LPVA and LPVB for the Telescope computers and the rest of the Vax cluster for the Instrument computers LPVG and LPVF.

If the SCSI board needs to be changed then the power to both the relevant machines and their devices should be turned off, anti-static procedures MUST be taken. Identify the relevant board, if you are not familiar with this and are unshure which is the SCSI board, then you may need to follow the SCSI cable back from one of the SCSI devices. Make a note where and how the SCSI controller pcb and it's cables are situated before extracting the board. There are no spare boards at present and only LPVA, LPVB, LPVF and LPVG have this version of multi-host shadowing controller. Replacement options at the moment are removing the board from the unused TCS machine. If a board has to be romoved then both host machines need to be brought down and switched off and then the SCSI devices switched off. The last SCSI device in the chain from the working machine will have to be terminated and then that machine can then be brought back up as normal. The board in the other machine can now be removed using anti-static procedures.

When changing or replacing a SCSI controller pcb make a note of all jumpers on both boards and then configure the jumpers of the replacement to that of the one removed.

Configuration of SCSI Controller

Both host computers should have been run down and switched off. The afore mentioned ribbon cable should be attached between the SCSI controller pcb and a VT terminal, ( the console terminal is ideal for this as it MUST be disconnected during configuration anyway and is of the correct rs232 settings.). Switch on only the host machine that you are going to configure. Doing this should bring up the MAIN MENU on the VT terminal as should halting the CPU, it may be neccessary to hit carriage return.

Choose option '5' for additional utilities and this will give you the following menu.

Choose option 'D' to display and configure the SCSI controller pcb. The present configuration will be shown. The following is taken from LPVB and is an example of what you might expect.

You should make a note of the present configuration.

Note DEV7 is set for SCSI ID 6, this is set by the jumpers on the SCSI controller pcb, one host needs to be set to ID 6 and the other host set to ID 7 which leaves a maximum of six devices that can be connected on ID 0 to ID 5.

You will also be prompted CHANGE COFIGURATION (Y/N) Unless you wish to reconfigure then you should select 'N' . If it is required then now is the time to Re-Configure the controller and selecting 'Y' will take you to the next menu.

It is IMPORTANT to Reset the controller to the default settings by selecting 'Z' first before beginning to configure. This is included in the following configuration scripts. Now select 'C' to Reconfigure a Device, the following is a rough transcript of what follows, the first is for the TCS and the second should be followed for the ICS unless changes have been made since this description was written or updated.

ex-TCS Configuration

This describes the old LPVA/LPVB TCS and not the Alpha based TCS which does not have a CMD controller

Select 'Z' to reset to default parameters
Change Configuration (Y/N) Y
Multihost ? (Y/N) N
Select 'R' to toggle SCSI reset and set SCSI reset to off
Change Configuration (Y/N) Y
Select 'C' to reconfigure device
No. of disk units (Including Shadow units) (0-7) 2
No. of shadow sets (0-1) 1
Break unit LUN offsets (min 2) 2
DU0 to be configured (Y/N) Y
DU0 SCSI id (0-7) 0
DU0 LUN? (0-3) 0
Shadow exist? (Y/N) Y
Enable shadow set (Y/N) Y
Shadow set already aligned (Y/N) Y
DS0 SCSI id (0-7) 1
DS0 LUN? (0-3) 0
No. of tapes (0-5) 1
MU0 to be reconfigured (Y/N) Y
MU0 SCSI id (0-7) 2
Change Configuration (Y/N) N
The SCSI controller now scans the devices and displays the configuration.
Change configuration (Y/N) N
To finish and return to main menu press 'BREAK'

ICS Configuration

Select 'Z' to reset to default parameters
Change Configuration (Y/N) Y
Multi-Host ? (Y/N) Y
Enter lowest host id (0-6) 6 (ie LPVF id is 7 and LPVG id id 6)
Cannot Auto-Config - Ignore This Message
Select 'R' to toggle SCSI reset and set SCSI reset to off
Change Configuration (Y/N) Y
No. of disks (including shadow units) (0-7) 5
No. of shadow sets (0-2) 2
Break unit LUN offset (minimum 5) 5
DU0 to be configured (Y/N) Y
DU0 SCSI id (0-7) 0
DU0 LUN (0-3) 0
Shadow unit exist (Y/N) Y
Enable shadow set (Y/N) Y
Shadow set already Aligned (Y/N) Y
DS0 scis id (0-7) 1
DS0 LUN (0-3) 0
DU1 to be configured (Y/N) Y
DU1 SCSI id (0-7) 2
DU1 LUN (0-3) 0
Shadow unit exist (Y/N) Y
Enable shadow set (Y/N) Y
Shadow set already Aligned (Y/N) Y
DS1 scis id (0-7) 3
DS1 LUN (0-3) 0
DU2 to be configured (Y/N) Y
DU2 SCSI id (0-7) 4
DU2 LUN (0-3) 0
No. of tape drives (0-2)
MU0 to be reconfigured (Y/N) Y
MU0 SCSI id (0-7) 5
MU0 LUN (0-3) 0
Assign quorum disk (Y/N) N -(IMPORTANT)
Update drive configuration block (Y/N) Y
Now configuration shown
Change Configuration (Y/N) N
SCSI card nows scans and displays devices
Change Configuration (Y/N) N
To finish and return to main menu press 'BREAK'

Below is an example configuration taken from LPVG

In essence that is it, switch off Vax machine remove ribbon cable and plug console terminal back into Vax, switch on and reboot.

REMEMBER TO USE ANTI-STATIC PROCEDURES WHEN REMOVING AND TRANSPORTING ANY PCB'S

FINALLY PUT EVERTHING BACK WHERE YOU GOT IT FROM AND LABEL ANY SUSPECT FAULTY BITS, THEN INFORM CFG WHAT YOU HAVE DONE AND WHY.