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

Jason Thorpe <[email protected]> Sun, 31 May 2026 10:39:50 -0400
Newsgroups gmane.os.netbsd.devel.kernel
Message-ID <[email protected]>

> On May 31, 2026, at 10:21 AM, Thor Lancelot Simon <[email protected]> wrote:
> 
> Huh.  I wonder how it got populated.  I'm vaguely remembering they might
> have had a "format" utility or something.

Probably?  (Still hunting, at least until my flight starts boarding.).  And it appears they had ioctls for getting the bad144 table from the driver in addition to setting it.

> Means moving a drive physically from a DEC system to a Sun VME system
> would have lost the bad block table, right?  I remember seeing exactly
> that done a few times with CDC drives that went from VAXen with Emulex
> controllers to Sun replacements which I expect had Xylogics controllers.
> I guess to do this safely must have required a low-level reformat by
> something that wrote the bad144 data in the expected byte order.

Yes, I suspect that’s what was needed, and the format utility would have either fixed the bad sectors or simply rewritten the bad144 table based on what it encountered during the format operation.

-- thorpej