Re: Sharing data between Debian and NetBSD on the same machine

[Andrew Randrianasulu <randrianasulu%gmail.com@localhost>]

On Tue, Jan 13, 2026 at 2:39 PM Ramiro Aceves <ea1abz%gmail.com@localhost> wrote:
>
>
>
> El 13/1/26 a las 11:52, Riccardo Mottola escribió:
> > Hi,
> >
> > Ramiro Aceves wrote:
> >> 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 follow this discussion. Currently, for this purpose I use FAT on an
> > external 1TB drive, I need to share With Linux and NetBSD, but also Mac
> > (also 10.5, 10.6) and OpenBSD and sometimes FreeBSD. FAT is Lingua
> > Franca, but has a lot of detail issues.
> > I don't care much for permissions - when I mount I assign them to
> > myself, works.
> >
>
> Hi Riccardo,
> Thanks so much for sharing your experience with FAT.
>
>
> > I do not have filename issues, but I have timestamp issues! Some OSs
> > store dates in UTC format which is I think wrong, it should be local
> > time from my understanding. I don't know exFAT status here.
> >
> > Also, the 2GB file limit can be one if movies, DVD ISO's are stored.
> > Nowadays NTFS is often used, but on certain OSs it is read-only if
> > commercial drivers are not used.
> >
>
> I am not a moovies fan but sometimes I record loong audio files, or long
> RF I/Q signals captured by the ham radio SDR receiver for further
> analysis,  that files can easily outpass 2 GB size. So I discard FAT for
> now.
>
> > I was evaluating exFAT for that purpose: it seems "on paper" well
> > supported enough. What you write though scares me. I could try with with
> > an USB stick.
> >
>
> Well, it was a quick test yesterday before going to bed (dissapointing
> test). I always give short file names for my documents, avoiding "í",
> "á" "ü" and strange characters. But some stored files in my
> "/home/ramiro/CRUCIAL_DATA_DIRECTORY" have crazy loooong names. Files of
> downloaded music and also files of stored emails from Thunderbird that
> have the subject as the file name. Perhaps I should clean that names but
> there are something like 1000 files with that issue.
>
>
>
> > Linux has UFS support but I don't know how well it supports FFSv2.
> > Apparently Apple dropped it too? Time for testing.


I do the opposite - use my netBSD 10.1 formatted 1Tb drive when my
main Linux hdd (ext4/xfs) overflows with ISOs and qemu virtual
harddrives/images.

Works a bit slow, but so far without corruption.

bash-5.1$ uname -a
Linux slax 6.12.26-x64 #1 SMP PREEMPT_DYNAMIC Sun May  4 23:16:06 MSK
2025 x86_64 AMD FX(tm)-4300 Quad-Core Processor AuthenticAMD GNU/Linux

bash-5.1$ mount
tmpfs on / type tmpfs (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
/dev/sda1 on /mnt/sda1 type ext4 (rw)
/dev/sda2 on /mnt/sda2 type xfs (rw)
nfsd on /proc/fs/nfs type nfsd (rw)
nfsd on /proc/fs/nfsd type nfsd (rw)
/mnt/sda2 on /home type none (rw,bind)
/usr/local/lo5472.sfs on /opt/libreoffice-5 type squashfs (ro,)
none on /dev/shm type tmpfs (rw,size=10G)
debugfs on /sys/kernel/debug type debugfs (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/sdb5 on /mnt/zip type ufs (rw,ufstype=ufs2)



One idea I had but not tested is to use qemu with nvmm acceleration to
boot Linux from its separate hdd and share data from there via NFS.
I tried this in reverse (qemu from linux side booting NetBSD), but
then I need to edit /etc/fstab because both my drives are MBR not GPT,
and default  fsck action get confused when they change their names


In theory there is also UDF, but I had bad luck with it on cheap 128
gb flash drive and some random Linux kernel I compiled.
>
> We keep in touch for any discoveries in about this storage sharing issue.
>
> Regards.
> Ramiro.
>
> >
> >
> > Riccardo
>