Re: bad144 - how useful still? Because it's annoyingly ubiquitous.

[is%netbsd.org@localhost]

Hello,

On Sun, May 31, 2026 at 05:36:10PM -0400, Jason Thorpe wrote:
> 
> > On May 31, 2026, at 12:25 PM, Thor Lancelot Simon <tls%panix.com@localhost> wrote:
> > 
> > Yeah, I was thinking about that.  But having to create new filesystems is a
> > little different from having to do a full format in ignorance of which blocks
> > were already marked as bad.
> 
> It also probably wasn’t very common to do this kind of cross-platform
> device-swapping back then.  And I suspect that people who did it
> were perfectly OK with “welp, gotta low-level format!”.
> 
> (Actual grey-beards, please chime in!)

I've once witnessed a non-SCSI disk being repurposed: when the
Physics Institute in Bonn decomissioned their PDP-10, my then boss
(I was a student helper coder to the guy designing and building
ELSAs vacuum pump and pressure sensor network) saved one washing
machine format disk and connected it to his VAX 11/750. Of course
this involved reformatting - from 36bit * size * y sectors to 32bit
* 128 * z sectors, at a slight capacity loss. That was whatever
they ran on the PDP10 to VMS.

Myself, much later, I've repurposed one or two SCSI disks from a
former machine (sun2 or sun3 I think) of the workgroup I was working
for, found on a cupboard, after carefully using FORMAT to be sure
it was still sound and map all bad blocks. Unless wanting to transfer
the data (not in this case), we'd never put an old (or even newly
bought) disk into new use unchecked; you'd never find time to do
a destructive test and full restore if you'd see suspicious errors
later.

	-is