[Simh] SIMH VAXcluster - shadow disk issues

[Mark Pizzolato - Info Comm]

Hi Guys,

Nathan's idea to ask on the VMS newsgroup is good.  

Meanwhile, since you've started the discussion here in the simh list, we can look at this from the simh perspective.  

You clearly describe the network connectivity between these nodes, and since the cluster forms you must have good communication between them.

Good so far.

Can you provide the simh configuration files for each of these VAX instances?  These may be relevant to understanding what is happening.

Thanks.

- Mark Pizzolato

On , January 20, 2012 3:18 AM, Nathan Cutler wrote:
> Hi Lennert, if you don't get immediately effective help here, you 
> might try reposting your question on the VMS newsgroup - comp.os.vms - 
> disk shadowing comes up there frequently.
> 
> Nathan
> 
> On Fri, Jan 20, 2012 at 8:10 AM, Lennert Van Alboom 
> <lennert at vanalboom.org> wrote:
> > Hello there.
> >
> > I'm running into issues with disk shadowing in VMS between two SIMH 
> > instances.
> > My setup is as follows:
> >
> > - 2 SIMH VAX instances running VMS 7.3, fully licensed using 
> > hobbyist
> > licenses:
> >  WHISKY and COGNAC
> > - Networking was setup using the "taptap" method as described in 
> > http://www.retrocomputinggeek.com/retrowiki/SIMHNetworking
> > - Both SIMH network tunX devices are on the same bridge (br0) on the
> same
> > linux
> >  host
> > - DECnet and TCPIP configured and confirmed to be working on both
> machines:
> >  WHISKY (1.1, x.y.z.240), COGNAC (1.2, x.y.z.241)
> > - VAXcluster enabled between both instances: WHISKY has VOTES=1,
> COGNAC
> >  VOTES=0, cluster EXPECTED_VOTES=1 with no quorum disk
> > - ALLOCLASS for WHISKY is set to 240, COGNAC to 241
> >
> > The Linux host itself is a Xen virtual machine; this is the main 
> > reason why I didn't go for a "dedicated" network interface per simh 
> > instance, as this doesn't play nice with the bridges on the Xen VM 
> > host.
> >
> > At this point, I wanted to play with disk shadowing. Each of the 
> > SIMH
> VAXen
> > has
> > two disks; one for system (DUA0:), one 'spare' (DUA1:). Both are of 
> > type
> > RA90
> > (1GB). The idea was to shadow those two 'spare' disks.
> >
> > Commands issued:
> >
> > $ INIT/ERASE $240$DUA1: CLUSTERDATA
> > $ INIT/ERASE $241$DUA1: CLUSTERDATA
> > $ MOUNT/SYSTEM/CLUSTER DSA0: /SHADOW=($240$DUA1:,$241$DUA1:)
> CLUSTERDATA
> > CLUSTERDATA
> >
> > At this point, the shadow disk is being created and mounted on both
> nodes.
> > No
> > issues there. But the disk copy never actually kicks off:
> >
> > $ SHOW DEV CLUSTERDATA
> >
> > Device                  Device           Error    Volume         Free  Trans
> > Mnt
> >  Name                   Status           Count     Label        Blocks Count
> > Cnt
> >  DSA0:                   Mounted              0  CLUSTERDATA    2375847
> > 1   2
> >  $240$DUA1:    (WHISKY)  ShadowSetMember      0  (member of DSA0:)
> >  $241$DUA1:    (COGNAC)  ShadowCopying        0  (copy trgt DSA0:   0%
> > copied)
> >
> >
> > Even after 12 hours, it's still at 0%; I think it's safe to say it's 
> > not going to go up. Has anyone ever attempted to do disk shadowing 
> > between two
> SIMH
> > instances, and if yes, do you have any idea what might be causing 
> > this problem?
> >
> >
> > Thanks,
> >
> >
> > Lennert
> > _______________________________________________
> > Simh mailing list
> > Simh at trailing-edge.com
> > http://mailman.trailing-edge.com/mailman/listinfo/simh
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