Subject: Re: FOLLOWUP: Frustrations trying to install 1.2
To: None <rnestor@metronet.com>
From: Greg Earle <earle@isolar.Tujunga.CA.US>
List: port-mac68k
Date: 10/05/1996 20:27:26
>> While this is a perfectly cogent and reasonable observation, I don't think
>> it was the case in my situation.  I used the latest Mkfs from the stuff in
>> the NetBSD-1.2/mac68k directory on ftp.NetBSD.ORG, and as you can see from
>> the above, after having partitioned with APS I was able to successfully
>> Mkfs the partition.  And at this point in time, surely there are people in
>> NetBSD/mac68k land who are using Mkfs'd NetBSD partitions larger than 1 Gb?
>> (Also, in my case the partition size is actually something like 900-some-odd
>> Mb, i.e. < 2 ^ 21 512-byte blocks.)
> 
> It's not the size of the disk partition, but the physical block address 
> required to address the partition.  In your original post, you had a 200 
> Meg Root&Usr partition that preceeded the 900 Meg partition.  And in 
> front of this there was the standard Driver Partition and Partition Map.  
> The block numbers required to access the end of the 900 Meg partition 
> would have exceeded the 2^21 boundary in this case, and Mkfs would 
> truncate those addresses without warning.

Ah, OK, now I gotcha.  I think the original had the 256 Mb Mac HFS partition
first (the Root&Usr was the 900+ Mb partition, actually), but I see your
point.  I guess if there was something like 100 + Mb of wrap-around, it's
interesting that it didn't blow away the Partition Map and Driver Partition
as well; then again, the superblock backups and other filesystem housekeeping
blocks only come along every so often in each cylinder group, so I guess it
could easily skip the 128 or so blocks these two things take up.

In other words, the bottom line seems to be, "make sure your NetBSD partitions
are no longer than 1 Gb (minus the Partition map and Driver Partition sizes),
and really really make sure that the NetBSD partition(s) are at the beginning
of the disk".  (I'm not sure, but I have a sneaking feeling that Silverlining
went and re-arranged the partition locations on me and put the Mac HFS one
first.)

Weird; the SunOS SCSI driver had this very same problem up until a few
years ago:

Patch i.d.	Description
----------	-----------
100343-06    SunOS 4.1.1: sd.o patch to access SCSI drive capacity beyond 1 GB.

Thanks for clearing that up.

	- Greg