Re: creating FFS2 file-system with makefs on linux

[Lloyd Parkes <lloyd%must-have-coffee.gen.nz@localhost>]

On 29/09/20 8:40 am, Pierre-Philipp Braun wrote:
> (I am answering both Lloyd and Christos here, as I couldn't get a 
> grasp on the second email, and to keep the Message-ID dance)

Sorry about the Message-ID dance. I'll try and avoid that in future.

> The workaround that I use is to create a small image, write it to 
> large partition, and then use /etc/rc.d/resize_root when booting the 
> image.
>
> Thanks Lloyd.  So here's how I created and increased the size of the 
> image:
>
>     tools/bin/nbmakefs -t ffs -o v=2,o=time -s 2g netbsd.ffs2 tree/
>     dd if=/dev/zero bs=1G count=6 >> netbsd.ffs2
>         fallocate --dig-holes netbsd.ffs2

Is this with NetBSD-current? My experience is with 9.0 and I have root 
filling almost all of a 500GB disk on a couple of NUCs. I thought the 
resize_ffs program refused to resize the v2 filesystems that I started 
with, but maybe it was just complaining about the log and I'm 
misremembering. Either way, my 9.0 systems are running with FFSv1.

Maybe you could build with something like

    nbmakefs -N tree/etc -x -F tree/METALOG.sanitised -s 2g -f 100000 
netbsd.ffs tree/

This is close to what I used to build my images.

> I also tried to do it manually in single user mode:
>
>     resize_ffs /dev/xbd0a

Running resize_ffs directly is most hazardous. I've got it wrong quite a 
lot. You have to make sure that you reboot without even flushing the 
superblock (reboot -n). A readonly mount isn't quite as readonly as it 
might be.

Also, you need to specify the raw device /dev/rxbd0a, not the block device.

Cheers,
Lloyd