Ramiro Aceves <ea1abz%gmail.com@localhost> wrote:
> After some time using and understanding NetBSD, I have been gaining
> confidence with the OS. I would like to progressively increase the
> importance of the tasks that NetBSD handles on my primary amd64
> daily-work machine (an Intel NUC 8i7BEH).
>
> I have been a happy Debian user for 25 years and have accumulated around
> 100 GB of genuinely useful data (schematics, web pages, programs, music
> scores, office work, RF electronics designs, simulations, PCB designs,
> documents, audio files, etc.). At the moment, I spend most of my time
> ?playing? with NetBSD, but I am getting tired of rebooting into Debian
> just to perform certain tasks or simply to access some files.
>
> I do not want to completely replace Debian, since some programs I rely
> on do not exist on NetBSD at the moment (and that would complicate my
> life too much). I also dislike the current trends in the Linux world,
> which is what originally led me to explore the BSDs. Ideally, I would
> like to maintain both operating systems with as little effort as possible.
>
> The two internal SSDs are already full, and their partitions cannot be
> modified. Therefore, I am considering using a WD Elements 2 TB USB drive
> for this purpose. This drive would store all my useful data and would be
> regularly backed up to other drives using rsync, as I already do. Both
> operating systems will be able to read and write the files.
>
> I initially thought about using an exFAT filesystem via FUSE, but as
> soon as I started rsyncing data from Debian to it, I encountered errors
> related to long and unusual characters in file names. Additionally,
> exFAT lacks proper permission support.
>
> Can I use an ext2 filesystem from NetBSD with confidence? Are there any
> other good alternatives for this use case?
>
I've been using an ext2 partition as a shared commons between Debian and
NetBSD on an old 32 bit system for a few years now and it mostly works
fine, though as 32 bit systems get dropped I'm using it much less and
most of the shared files are plain text. I seem to recall rsync backups
of the NetBSD system hanging on the Commons filesystem (see below) so I
only run rsync on Commons from the Debian side. I haven't noticed the
timestamp issue mentioned in this thread but both Debian and NetBSD are
doing similar NTPD clock setting.
My setup (for commmon uid "jgw"):
--
# Debian:
$ uname -a
Linux slimline 6.1.0-42-686 #1 SMP PREEMPT_DYNAMIC Debian 6.1.159-1 (2025-12-30) i686 GNU/Linux
$ mount -t ext2,ext4
/dev/sda4 on /home/jgw/Commons type ext2 (rw,relatime)
/dev/sda1 on /boot type ext2 (rw,relatime)
/dev/sda2 on / type ext4 (rw,relatime,errors=remount-ro)
# NetBSD:
$ uname -a
NetBSD slimline 10.1_STABLE NetBSD 10.1_STABLE (GENERIC) #0: Fri Dec 26 12:53:23 UTC 2025 .../GENERIC i386
$ mount -t ffs,'puffs|p2k|ext2fs',umap
/dev/dk2 on / type ffs (log, noatime, local)
/dev/dk3 on /media/jgw type puffs|p2k|ext2fs
/media/jgw on /home/jgw/Commons type umap
$ egrep 'ffs|ext2fs|umap' /etc/fstab
NAME=NetBSD / ffs rw,noatime,log 1 1
NAME=Commons /media/jgw ext2fs rw,rump,auto
/media/jgw /home/jgw/Commons umap rw,-g/GID_remap,-u/UID_remap,auto
--
The id(1) tool was used to populate the /GID_remap and /UID_remap files.
The disk is setup with gpt partitions with NetBSD booted via GRUB/
--
$ gpt show wd0
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 2014 Unused
2048 2048 6 GPT part - BIOS Boot
4096 1046528 1 GPT part - EFI System
1050624 268435456 2 GPT part - Linux data
269486080 125829120 3 GPT part - EFI System
395315200 83886080 4 GPT part - Linux data
479201280 9195520 5 GPT part - NetBSD swap
488396800 335 Unused
488397135 32 Sec GPT table
488397167 1 Sec GPT header
--
In above indicies 2-4 are Debian (ext4), NetBSD (ffs), Commons (ext2).
Interestingly, dkctl(8) shows the FFS partition as type "msdos":
--
$ sudo dkctl wd0 listwedges
/dev/rwd0: 6 wedges:
dk5: e8b85d79-899f-4cd6-964e-af3db098e992, 2048 blocks at 2048, type:
dk0: Boot, 1046528 blocks at 4096, type: msdos
dk1: Debian, 268435456 blocks at 1050624, type: ext2fs
dk2: NetBSD, 125829120 blocks at 269486080, type: msdos
dk3: Commons, 83886080 blocks at 395315200, type: ext2fs
dk4: Swap, 9195520 blocks at 479201280, type: swap
--
Weird eh?
Anyway, maybe this helps? Would be interested to get feedback
if you opt for a similar setup.
Have fun,
beaker