On Wed, Sep 28, 2022 at 04:52:43PM +0000, Pham Ngoc-Dung wrote: > Hi. On my hard drive (wd0, MBR), I have 3 partitions originally for Linux, > including a boot partition (ext2 formatted), and another partition with > NetBSD installed. > For a reason I wanted to mount the Linux boot partition, which should have > been easy since ext2 is supported by NBSD. But except fdisk where it showed > up, I couldn't find it anywhere, nor a way to mount it. > A little bit more of research, then I found out about dk(4). I tried to > rebuild the kernel with DKWEDGE_METHOD_MBR uncommented. It did boot from that > kernel, but it couldn't mount my root device, However the 3 Linux partitions > were now detected: > > [4.8364408] wd0 at atabus0 drive 0 > [4.8364408] wd0: <ST500LT012-9WS142> > [4.9467467] dk0 at wd0: "wd0e" > [4.9467467] dk1 at wd0: "wd0f" > [4.9467467] dk2 at wd0: "wd0h" > [5.0676107] boot device: wd0 > [5.0676107] root on wd0a dumps on wd0b > [5.0676107] vfs_mountroot: can't open root device > [5.0676107] cannot mount root, error = 16 > [5.0676107] root device (default wd0a): > > Is there a workaround or a fix to this behavior?
You can hardwire / to dk2 (or whichever it is), but actually simpler is to not use a kernel with DKWEDGE_METHOD_MBR and instead do the setup at runtime from userland: find the start sector and size of the partition you want from fdisk output and use "dkctl addwedge ..." to configure it as dkN, then mount that dkN. Martin
