[Info-vax] Greater than approx 16GB disk leads to UNXSIGNAL crash

[Stephen Hoffman]

On 2021-05-28 11:07:55 +0000, Volker Halle said:

> The problem itself seems to be in MOUNT, when setting up the geometry 
> of the disk. Solutions i.e. patches may exist in the V7.2 remedial 
> stream or higher.

There was an easily-reproduceable bug in a related area of MOUNT.

Load a blank CD into an optical drive, and MOUNT it.

Kernel loop.

Using MOUNT with a blank CD (unsurprisingly) got somewhat odd responses 
from the device, and the drivers and MOUNT then mis-handled it, leading 
to an un-deletable process looping in kernel mode.

Only fix was a reboot, after dropping the process priority of the 
looping process to let it tussle with null until the reboot was 
feasible.

IIRC, both MOUNT and the related device drivers got fixes as a result 
of that particular case. And IIRC, it was a bug in the MOUNT code 
intended to find the home block / alternate home block.

ps: CANASTA/CCAT/etc was handy to have around. Unfortunately, it 
usually just left me with a pile of gnarly crashes, after having used 
it to eliminate all the known crashes.


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