freezing on unmountin ext2fs USB device

Hello,

running FreeBSD 16.0-CURRENT #4 master-n282101-c8cf5a99f82b: Sun Nov 23 13:56:23 CET
2025 amd64 I'm running into a serious problem when mounting an ext2fs formated USB Flash
device (512GB). The devince contains files written by a Linux system, mounting the USB Flash
via extended4fs, the size of the written datafiles is > 128GB. Deleting those files larger
than some 20GB results in an I/O error reported by FReeBSD (# sudo rm /mnt/USB/filename).
Unmounting the ext2fs after deletion (sudo umount /mnt) results in a total freeze of the box.
No crash, no core dump, nothing. I waited almost an hour hoping for recover. I have to
physically switch off the box.

I checked with other USB flash I have at hand, one Samsung 256 GB, ZFS - no problem, another
128GB, UFS, no problem and several much smaller (4 - 64GB) with FAT or UFS filesystems, all no
problem.

I can not figure out whether it is the USB flash drive itself, the size or the ext2fs itself
causing the problem.

Does anybody see similar problems or do have an tip to investigate without risking my box'
health switching it on/off on failure?

Thanks in advance,

oh 


-- 

A FreeBSD user