Re: hang/panic: newfs of 4.3 FFS (filesystem only) on vnd1

[Chris Hanson <cmhanson%eschatologist.net@localhost>]

On Aug 10, 2026, at 7:41 PM, matthew green <mrg%eterna23.net@localhost> wrote:
> 
> what was the actual panic?  this seems unexpected.

Unfortunately I forgot that I could just grab a screenshot of the panic from the remote console on my HP so I don’t have a record of it.

I also haven’t been able to reproduce it.

What I have found is that I can’t create a MacMach-compatible disklabel from NetBSD, but I can manipulate one. But unfortunately I can’t create *or manipulate* a MacMach-compatible (4.3BSD Tahoe) filesystem from NetBSD, because MacMach will complain about an invalid superblock.

Fortunately the MacMach installation RAM disk does include ftp, ifconfig, and route, so once I can get networking working I’ll be able to populate the filesystem that way. For posterity, the full path to getting this working will be, using the MAME Mac Iicx emulator and a modern NetBSD system:

1. Create a large disk image with Apple partitioning and an Apple_Free partition.

2. Boot MacMach single-user with that disk image attached, and use mac2part on MacMach to convert the disk image’s Apple_Free Apple partition to a MacMach Apple partition.

This produces a MacMach Apple partition with a Tahoe disklabel at front that has “a-g” Tahoe partitions. Why mac2part does this is a mystery, since MacMach is claimed to only support one Tahoe partition per SCSI disk.

3. Using NetBSD, edit that disklabel to contain only an “a” Tahoe partition spanning the entire MacMach Apple partition, which is what MacMach actually wants.

4. Boot MacMach single-user again, and newfs a Tahoe filesystem on the “a” Tahoe partition that spans the entire MacMach Apple partition.

5. Boot MacMach to its installation tool, which can retrieve/chmod/chown the entire system from an FTP server.

6. Save and archive the pristine should-be-bootable MacMach disk image so nobody ever has to figure this out again...

Unfortunately now I’m hitting a networking issue with MAME at step 5, but I expect that to be temporary. And I could always switch to using real hardware for it...

  -- Chris