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SC10 termination issue in MC-SG environment

 
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Anthony_4
Advisor

SC10 termination issue in MC-SG environment

does SC10 require in-line-terminator if it is used on share bus?
I know that a Fast wide disk enclosure on a shared bus require in-line-terminator to connect to hosts. If one host require service, you may shutdown a host and disconnect scsi cable from that host when the application is up on the other host.
Could anybody explain this?
7 REPLIES 7
melvyn burnard
Honored Contributor

Re: SC10 termination issue in MC-SG environment

As the SC10 is connected using LVD SCSI, you should use the in-line termninating cables to connect it to a shared bus in an MC/SG environment.
This allows you to disconnect the cable from teh server interface WITHOUT breaking the SCSI bus if you need to shutdown a node and disconnect it from the bus.
My house is the bank's, my money the wife's, But my opinions belong to me, not HP!
Vikas Khator
Honored Contributor

Re: SC10 termination issue in MC-SG environment

Hi,

Yes you need to use in line terminators. Basically anything SCSI that's being shared need in line termination.
Keep it simple
Anthony_4
Advisor

Re: SC10 termination issue in MC-SG environment

Thanks, Melvyn and vikas. but in fact, I did a test today. without in-line-terminator, I disconnect scsi cable from one L2000, the other L2000 could still access the shared data in the shared SC10. no scsi reset occured during the test.
anybody could explain to me the electronic feature for ultra2 scsi?
Tony
Patrick Wessel
Honored Contributor

Re: SC10 termination issue in MC-SG environment

Because it works once does not mean that it works every time. The SCSI standard defines that you need a termination on both ends of the bus.
The following whitepaper describes the Ultra2 SCSI bus:
http://www.scsita.org/aboutscsi/whitepaper/ultra2.pdf
There is no good troubleshooting with bad data
LEJARRE Patrick
Advisor
Solution

Re: SC10 termination issue in MC-SG environment

You should order the following auto-terminated VHDCI / Ultra SCSI cable:

Part number : A5272A opt 862.
melvyn burnard
Honored Contributor

Re: SC10 termination issue in MC-SG environment

Just because the test worked once by no means says it will work in the future. You have what is basically an unsound connection, due to non-termination on the bus, and this could lead to all sorts of grief, including possible corruption.
Also, from a High Availability viewpoint, this is unsupported.
For the extra cost involved, use the cables.
My house is the bank's, my money the wife's, But my opinions belong to me, not HP!
Anthony_4
Advisor

Re: SC10 termination issue in MC-SG environment

Thank you all for the information. I checked the PSP of SC10. This new option 862 was added just in July .
thanks.
Tony