regading scsi cable

[#1]

hi

we have two DS-20 Alpha servers with 2 CPU, 4GB RAM & 500 MHz Processor and we are trying to establish a SCSI cable VMS cluster setup among these two servers.

We have configured our servers as follows:








We are getting problem in recognizing the storage box. When we connect the Storage box with the DS-20 server using 68-pin SCSI cable, DS-20 is not able to recognize it moreover, after connecting DS-20 to storage box it is not even showing its internal disks. The same problem occurs when we connect two DS-20 Alpha server using 68-pin SCSI cable without using the Storage box both the server are not showing their internal disks.

Can you please help us how can we make DS-20 server to recognize storage box or how one DS-20 Server can show other DS-20 disks also after connecting each other using SCSI Cable. Is there any system changes or environmental variable to be set for the same.

[Willem Grooters]

I'm missing the picture - it's not shown.

Just a guess: from your description, my guess is that you are trying to establish shared SCSI. I struggle with this myself ;)
This requires specific hardware in DS-20. According the documentation, you'll neeed KZPSA SCSI controllers in EACH box - I tried KZPBY-CY but found it not working properly (but that may have be related to firmware).
You will have to do some environmental changes as well. You'll need to use port-allocation for the SCI but that connects to shared SCSI. You can achieve this by running CLUSTER_CONFIG_LAN.COM, one of the options is usage of shared SCSI. Both your DS-20 systems MUST have the same number on this controller. beware that each system must have a different SCSI-ID on this bus: If one system has 7 (default), you MUST specify the other system a lower number. 6 is the nmost obvious one.
It might be that the controller in the storage box has some requirements as well - but that depends on the controller.

Besides this, you'll have to setup each node as a cluster node and disk server. This is a normal requirement. Again, this is best achieved running CLUSTER_CONFIFG[_LAN].COM.

SCSI alone - without a storage box --- I haven't tried that, but AFAIK above still holds.

HTH so far

WG

[Willem Grooters]

Before I forget: you NEED differental SCSI for shared SCSI.

WG

[#4]

please find the image in atatchment


regards
ajaydec

[Richard Brodie_1]

"SCSI alone - without a storage box --- I haven't tried that"

It would be a singularly pointless thing to do, since the SCSI isn't used as a CI. But you probably knew that.

ajaydec: like Willem says, you need to be using a differential controller for shared SCSI. You can't use the one that the internal disks are on.

[#6]

I am using Differential SCSI only. But as soon as I am connection SCSI cable to the server, server is hanging up and when I removed it, its working fine.
Actually I want to boot both the servers from the SCSI disk located in the storage box, for that DS-20 server should be able to recognize the DISK at the triplet point P0>>>, but when I am giving "show dev" over there its not showing any disks.

[Jan van den Ende]

ajaydec,

Look over Willem's answer again:
>>>
beware that each system must have a different SCSI-ID on this bus: If one system has 7 (default), you MUST specify the other system a lower number. 6 is the nmost obvious one.
<<<

You observed:

>>>
But as soon as I am connection SCSI cable to the server, server is hanging up and when I removed it, its working fine.
<<<

This is the clear symptom of NOT having all addresses unique on the SCSI bus.

Change the Host bus address on ONE of the systems, and then be aware that NO other device is on that address nor ANY device address is duplicate).

hth

Proost.

Have one on me.

jpe

[Willem Grooters]

What controller do you use on the storage box, and what type of SCSI controller do you have in the DS-20 ? (these two must be of the same type (KZPBA - contrary to what I stated earlier. The documentation isn't clear at all: "Guidelines for OpenVMS Cluster Configurations", chapter 6
(8.3: http://h71000.www7.hp.com/doc/82FINAL/6318/6318pro_006.html
7.3-2: http://h71000.www7.hp.com/doc/732FINAL/6318/6318PRO.HTML)

states KZPBA as a requirement for SCSI failover, not KZPSA, but that might not be your intention - follow the manual here.

The manual only covers HSZ70 aned HSZ80 controllers in dual, fail-over configuration - so it really is needed to know what controller you're using.

[#9]

Can we use single ended SCSI cable to make a SCSI Cable cluster system.
I tried to use single ended SCSI Cable storage box and connect it to DS-20 Alpha server which also has single ended SCSI port, this time i changed the default pka, pkb and pkc host id (PKA_host_id) value to 4,5,6 on one of the server and on other system it was 7, but then also its not working.
How shud i go about now.

[Steven Schweda]

> Can we use single ended SCSI cable to make
> a SCSI Cable cluster system.[?]

I thought that I read somewhere that you
can't connect two systems and a disk without
exceeding the maximum cable length for a
single-ended (fast/ultra/whatever) SCSI bus.
I thought that that was why only differential
SCSI was supported. No bets, however.

Doesn't the VMScluster Configuration Guide
(or something like that) explain this stuff?