I also do what beaker does, ext2 as a common share between Linux and NetBSD.
Someone wrote up a good article on doing what beaker and I do: https://itsfoss.community/t/setting-up-a-shared-filesystem-between-netbsd-and-linux/14732 On Tue, Jan 13, 2026 at 9:57 AM beaker <[email protected]> wrote: > Ramiro Aceves <[email protected]> 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 >
