Subject: Re: Supporting sector size != DEV_BSIZE
To: None <tech-kern@netbsd.org>
From: Darrin B. Jewell <jewell@mit.edu>
List: tech-kern
Date: 06/26/2002 04:24:45
Let me take a step down in tone.  It is not my intention to attack the
work you are doing.  In general, I believe you know what you are
talking about, are making the correct decisions and are working in the
right direction.

Bill Studenmund <wrstuden@netbsd.org> writes:
| > I'm going to attempt to hold my ground on this point.
| 
| Darren, why are you jumping into this thread so late and then "holding
| your ground?" We're been over a lot of this stuff already.

Good point.  Let me retreat and suggest that changing DEV_BSIZE
is a difficult goal.  I am looking forward to it being successfully
accomplished.

| > Even if it does work, NetBSD 1.5 kernels compiled with differing
| > values for DEV_BSIZE will have completely incompatible filesystems,
| > if for no other reason than DIRLBKSIZ will have changed.
| 
| Yes, they will be incompatable. We know that. We however want to make them
| work as part of this. :-)

Good.  This is mostly what I was getting at.

I am hearing you say that when you are done, I will be able to take a
disk with 2k sectors that has a filesystem that was created on NetBSD
1.5 with DEV_BSIZE=2048, dd it onto a disk that has 1k sectors and
then mount it on my system compiled with DEV_BSIZE=512.

This will make me happy.

| > Probably not, although there was not enough information in the part I
| > sent to see what they units they use for the cylinder block count or
| > quota counts.  Since I can't remember offhand what I found last time
| > I checked, I will have to look it up.
| 
| Uhm, that's why I wanted to see an inode. :-)

Ok, I have a UFS filesystem image from a NeXT 1k scsi disk as well
as the UFS filesystem image from the NeXTstep 3.3 install CD (2k media)
If there is a particular analysis you would like, please let me know.
I will examine the inode again and let you know what I see.  I hope to
have the time this weekend or over the upcoming holiday.

| Darren, why are you imposing requirements? Yes, everything seems
| reasonable below, but why are you jumping in at the end of a thread and
| imposing requirements on it?

These were my requirements, please do not consider them imposed on you.

Thanks,

Darrin