Re: adding newfs_ext2fs and mount_ext2fs to ramdisk flist

[Blair Sadewitz <blair.sadewitz%gmail.com@localhost>]

On Sun, Jun 17, 2012 at 10:36 AM, Greg Troxel <gdt%ir.bbn.com@localhost> wrote:
>
>
> If they are added, it seems i386 and amd64 should both get them.
> How much more space is needed?

Umm, I don't think much. ;-)

>
> It sounds like {mount,newfs}_ext2fs are needed to set up a small
> partition to store the pvgrub config/kernel, and then you are using ffs
> for NetBSD to use as a real partition.
>
Well, that is what a lot of people do.  My particular provider uses
file-backed disks in lvm; the disk is /dev/xvda1 in linux (there is no
xvda).

> Did you consider just using ext2fs for the entire netbsd disk?  As a
> long-time BSD user, that feels odd, but I wonder if people have
> opinions/data on how well it works

I would rather use ffs, considering that it does work. ;-)

> I've had the impression ext2fs had
> consistency issues with unclean shutdown, but also that those were fixed
> in Linux, and of course our code is different.
>
> As for ffs/ufs, it is confusing, but basically "-O 2" leads to
> UFS2/FFSv2.   FFSv1 can have various sublevels; see -c option to
> fsck_ffs.  It is common to use -c 5 which leads to ufs2-style
> superblocks in a ffsv1 layout.

I'm not positive, but IIRC, I tried going to level five and it didn't
boot anymore.
>
> dumpfs is helpful; it will show you the fs-level magic number and the
> superblock format, and a fs level.

Yeah, I figured that out somewhere along this enchanted journey of linuxness.

>
> i think 'newfs -O 1' leads to the same as fsck-ffs -c 4, but I'm not
> sure.
I think that is what happens.
>
> You said pvgrub can read ffsv1.  Do you know if that's with ufs2
> superblocks, or the older superblocks, and what the version of pvgrub
> is?
>

That is with whatever sysinst does when you choose ffs2.  I am unsure
of the version of pv-grub.  I only just found its repository the other
day. ;-)  I think that also happens if you choose to go to level 5, as
I mentioned above.

> I don't know of any compelling reasons to use ufs2 vs ffsv1 for smallish
> filesystems (where smallish is certainly up to tens of GB).
>
I don't really, either, other than it was the default and I am trying
to make this as painless as possible for everyone. ;-)

> I tend to use ffsv1 (with v2 superblocks) for root filesystems, and ufs2
> for the bigger data ones.

Well, my whole filesystem is 'only' 40GB.  Should I just not care?  I
haven't even been using multiple slices yet, heh, because I don't even
know what I'm going to end up using.  If you have any suggestions for
a layout, though, I'll take note. ;-)

Regards,

--Blair