Re: how to connect 2 nodes to a SCSI disk (cabinet)

[Steven Dake <sdake@mvista.com>]

Prakash,

I have seen using the AIC 39160 that the BIOS will lock up on one node 
if it receives a reset during BIOS device scan with two hosts.  There is 
really nothing you can do, but get Adaptec to fix their buggy BIOS.  I 
don't know if other brands have this similiar problem.  If you really 
want multi-host storage access, you should consider using FibreChannel 
which doesn't have these sorts of issues.

Thanks
-steve

Ranade, Prakash wrote:

>yes its the bios and i am using 
>
>Adaptec AIC7xxx driver version: 6.2.8
>aic7892: Ultra160 Wide Channel A, SCSI Id=14, 32/253 SCBs
>
>Prakash S. Ranade
>OCP - Oracle Certified DBA 8i, 9i
>205 776 2320
>
>"Lets document it and call it a feature"
>
>
>-----Original Message-----
>From: Eddie Williams [mailto:Eddie.Williams@steeleye.com]
>Sent: Friday, June 20, 2003 3:00 PM
>To: Ranade, Prakash
>Cc: linux-scsi@vger.kernel.org
>Subject: Re: how to connect 2 nodes to a SCSI disk (cabinet)
>
>
>
>I take it this "someone initialized ..." message is coming from the BIOS?  I 
>don't see anything like this in the SCSI driver source directory.
>
>I have used both the aic7xxx new and old doing clustering so with those 
>drivers and the cards they support I know it works.  If you are not using the 
>aic7xxx driver then it may be that the driver is not honoring the initiator 
>ID set in BIOS and so you have a conflict.
>
>I don't see below where you say what specific adapter you are using?  
>
>Eddie
>On Friday 20 June 2003 03:32 pm, Ranade, Prakash wrote:
>  
>
>>both hang at boot time...they both try to initialize the device and
>>hang..... if i boot node1 without starting node2 then node1 boots up but
>>then when i try to boot node2 then it keeps saying "someone initialized
>>channel A"....
>>
>>Prakash S. Ranade
>>OCP - Oracle Certified DBA 8i, 9i
>>205 776 2320
>>
>>"Lets document it and call it a feature"
>>
>>
>>-----Original Message-----
>>From: Eddie Williams [mailto:Eddie.Williams@steeleye.com]
>>Sent: Friday, June 20, 2003 2:24 PM
>>To: Ranade, Prakash
>>Cc: linux-scsi@vger.kernel.org
>>Subject: Re: how to connect 2 nodes to a SCSI disk (cabinet)
>>
>>
>>
>>Please define "there is a conflict when they try to initialize the bus."
>>
>>Do you have a SCSI analyzer seeing some conflict?
>>When you boot them both up, one or both hang?
>>One or the other can not read the fdisk when they boot?
>>
>>
>>Eddie
>>
>>On Friday 20 June 2003 02:55 pm, Ranade, Prakash wrote:
>>    
>>
>>>yes they can see the drive but there is a conflict when they try to
>>>initialize the bus...
>>>
>>>Prakash S. Ranade
>>>OCP - Oracle Certified DBA 8i, 9i
>>>205 776 2320
>>>
>>>"Lets document it and call it a feature"
>>>
>>>
>>>-----Original Message-----
>>>From: Eddie Williams [mailto:Eddie.Williams@steeleye.com]
>>>Sent: Friday, June 20, 2003 1:26 PM
>>>To: jansen, frank; Ranade, Prakash; Mike Dresser
>>>Cc: linux-scsi@vger.kernel.org
>>>Subject: Re: how to connect 2 nodes to a SCSI disk (cabinet)
>>>
>>>
>>>
>>>Depending on which adaptec card you are using you may need to set a
>>>jumper to force termination.  Some of the older Adaptec cards have "soft"
>>>termination. Meaning, when power is applied it will drive termination but
>>>when power is dropped termination is dropped.  For those cards setting a
>>>jumper will force termination even when the power is removed.  This is
>>>pretty important if you power off one server.
>>>
>>>It is probably safe to assume other wise but just to be sure, this is not
>>>a dual ported SCSI drive is it?  If so then it is not really a shared bus
>>>and in that case the drive would need to terminate both busses.
>>>
>>>I agree with Frank here, you want the hosts at 7 and 6.
>>>
>>>If you power the servers up one at a time can they see the drive OK? 
>>>Start simple.
>>>
>>>Eddie
>>>
>>>On Friday 20 June 2003 01:49 pm, jansen, frank wrote:
>>>      
>>>
>>>>This is fairly old technology, so I'll have to go back in my memory
>>>>banks, but here are my recollections on setting this up:
>>>>
>>>>- Change the topology so that there is no termination on either HBA and
>>>>use Y-cables with external termination, so that you can unplug either
>>>>host from the bus without taking down access for the other host.  The
>>>>topology will look as follows:
>>>>
>>>>    T   _______external SCSI driver______________   T
>>>>     \ /                                         \ /
>>>>      Y                                           Y
>>>>   node 1 							node 2
>>>>
>>>>The other option is to leave termination on both HBAs, inwhich case you
>>>>should never unplug anything.  Note that the bus must be arbitrated on
>>>>both ends.  Also be sure not to violate any length limits on your SCSI
>>>>bus. - ID settings: set one HBA to 7 and the other to 6.  The reason
>>>>for these numbers is that the arbitration scheme for SCSI runs 7 down
>>>>to 0 to 15 down to 8.  In your current configuration the disk has a
>>>>higher arbitration priority than the HBAs.
>>>>- Disable bus erset on power up on both HBAs; this will ensure that you
>>>>can power either host without clearing all outstanding requests on the
>>>>bus.
>>>>
>>>>If none of your pins are bent anywhere, this should work for sharing a
>>>>device.  Now you'll get to the fun part of 2 hosts coordinating access
>>>>to a single device.
>>>>
>>>>Good luck,
>>>>
>>>>Frank
>>>>
>>>>-----Original Message-----
>>>>From: Ranade, Prakash [mailto:prakashr@intgroup.com]
>>>>Sent: Friday, June 20, 2003 1:01 PM
>>>>To: Mike Dresser
>>>>Cc: linux-scsi@vger.kernel.org
>>>>Subject: RE: how to connect 2 nodes to a SCSI disk (cabinet)
>>>>
>>>>
>>>>isent it true that...
>>>>you cannot have two seperate SCSI controllers trying to maintain the
>>>>same bus.They will fight..for same bus?
>>>>
>>>>Prakash S. Ranade
>>>>OCP - Oracle Certified DBA 8i, 9i
>>>>205 776 2320
>>>>
>>>>"Lets document it and call it a feature"
>>>>
>>>>
>>>>-----Original Message-----
>>>>From: Mike Dresser [mailto:mdresser_l@windsormachine.com]
>>>>Sent: Friday, June 20, 2003 11:57 AM
>>>>To: Ranade, Prakash
>>>>Cc: linux-scsi@vger.kernel.org
>>>>Subject: RE: how to connect 2 nodes to a SCSI disk (cabinet)
>>>>
>>>>On Fri, 20 Jun 2003, Ranade, Prakash wrote:
>>>>        
>>>>
>>>>>node1 and node2 both running redhat linux 7.2...both have Adaptec
>>>>>scsi
>>>>>          
>>>>>
>>>>card in it...scsi disk is  DataSilo DS-100 (see attached manual) using
>>>>Seagate HD.
>>>>
>>>>        
>>>>
>>>>>node1:scsi id = 14 - scsi termination is disabled
>>>>>node1:scsi id = 15 - scsi termination is automatic (i tried all
>>>>>          
>>>>>
>>>>enabled/disabled/automatic nothing works)
>>>>
>>>>        
>>>>
>>>>>external scsi disk id = 0
>>>>>
>>>>>node 1 							node 2
>>>>>
>>>>>
>>>>>	---------external SCSI drive---------------
>>>>>          
>>>>>
>>>>Any internal connections on either SCSI card?
>>>>
>>>>If not, set both node's to enabled scsi termination.
>>>>
>>>>Mike
>>>>
>>>>-
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>>>>
>
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