[Info-vax] recognizing SCSI disks

[Phillip Helbig undress to reply]

In article <qn2igd$1ttt$1 at gioia.aioe.org>,
helbig at asclothestro.multivax.de (Phillip Helbig (undress to reply))
writes: 

> In article <qn2ci7$vrh$1 at gioia.aioe.org>,
> helbig at asclothestro.multivax.de (Phillip Helbig (undress to reply))
> writes: 
> 
> > Reason: Today, my electricity meter was supposed to be swapped out and, 
> > having no UPS, I powered down the cluster.  As it turned out, the guy 
> > who was to install it was sick and the company didn't call to cancel the 
> > appointment, so it was all unnecessary.  After powering up, one PWS 
> > seems to have died (nothing at the console prompt).  It could be that 
> > the battery is bad and it reverted to the SRM console and graphics 
> > output.  I'll swap in the spare and, if the removed machine otherwise 
> > looks OK, replace the battery and it will become the new spare.
> 
> Well, cluster is back with the original hardware.  :-)

Perhaps unrelated to the shutdown and power-off, or perhaps not, a BA356 
was making some loud noises.  It didn't sound like a bad disk, but you 
never know.  I removed them one by one, but the noise didn't go away.  I 
figured it was the fan or something.  So, I swapped the disks into 
another box.  This solved the problem, and the node is back in the 
cluster now.  Nice to have spare hardware sitting around; thanks to all 
who have given me stuff over the years (or, by now, decades).

I've never had a an expansion box itself fail, as opposed to the disks 
in it.

As the model was identical, I though that I could just connect it up and 
boot, but the console couldn't see the disks.  I power-cycled the 
machine (a PWS), and then everything is OK.

Why was it necessary to power-cycle the machine so that it could see the 
disks?  I remember once when I pulled a SCSI cable by accident; the 
disks (including the system disk )went into mount verification, then 
came back when I plugged the cable back in.  That seems much more 
dangerous than unplugging the cable at the console prompt.  Of course, 
it is a different box (but same connector at the top of the box, the 
removable one where the cable plugs in), but surely the SCSI controller 
doesn't need the ID of the box (assuming that there is one).