Subject: NeXT formatted disks (was Re: next68k port status?)
To: Darrin B. Jewell <dbj@NetBSD.org>
From: Michael Wolfson <email@example.com>
Date: 10/16/2003 21:16:44
On Thursday, October 16, 2003, at 06:27 AM, Darrin B. Jewell wrote:
> NeXT used 1024 byte sectors by default, but although i'm pretty
> sure that by NeXTstep 3.3 at least it could use filesystems with
> other sector sizes.
Well, I can confirm that. I plugged a new disk into NeXTSTEP 3.3 and
it newfs'ed it and set it up as a 512 byte/sector disk. It did not do
a low level format.
From the NeXTSTEP dmesg:
SCSI 53C90A Controller, Target 7, as sc0 at 0x2114000
SEAGATE ST51080N Rev 0958 as sd0 at sc0 target 0 lun 0
Disk Label: Disk
Disk Capacity 1030MB, Device Block 512 bytes
QUANTUM FIREBALL1080S Rev 1Q04 as sd1 at sc0 target 2 lun 0
Disk Label: Fubar
Disk Capacity 1042MB, Device Block 512 bytes
The interesting thing is that to the OS (NeXTSTEP), it believed that
they were 1024 byte sectors. In particular /etc/disktab says that the
only sector size supported is 1024 bytes (DEV_BSIZE). Also, the
disklabel shows that it's just like NetBSD: fsize is 1024 and bsize is
And, when NetBSD probes these disks:
sd0 at scsibus0 target 0 lun 0: <SEAGATE, ST51080N, 0958> disk fixed
sd0: 1030 MB, 4826 cyl, 4 head, 109 sec, 512 bytes/sect x 2109840
sd0: async, 8-bit transfers
sd1 at scsibus0 target 2 lun 0: <QUANTUM, FIREBALL1080S, 1Q04> disk
sd1: 1042 MB, 3835 cyl, 4 head, 139 sec, 512 bytes/sect x 2134305
sd1: async, 8-bit transfers
Still 512 bytes/sector.
My vaguely educated guess is that they just hid that layer of
complexity and called the "sector" size of the disk 1024 bytes.
I'd be happy to send you a sample files system for analysis if you
wanted to support the NeXT filesystem.