ext2 or ext3 usage

[Andrey Oktyabrskiy]

Good day.

Is it possible to mount ext2 or (better) ext3 FS in r/w mode under dfly? 
I've tried to mount both with the same result:
$ sudo mount_ext2fs /dev/da0s2 /UNIT
mount_ext2fs: /dev/da0s2: Invalid argument
$ sudo fdisk /dev/da0
******* Working on device /dev/da0 *******
parameters extracted from device are:
cylinders=121126 heads=256 sectors/track=63 (16128 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=121126 heads=256 sectors/track=63 (16128 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165,(DragonFly/FreeBSD/NetBSD/386BSD)
     start 2079, size 134204931 (65529 Meg), flag 80 (active)
         beg: cyl 0/ head 33/ sector 1;
         end: cyl 1023/ head 255/ sector 63
The data for partition 2 is:
sysid 131,(Linux filesystem)
     start 134219776, size 1819303936 (888332 Meg), flag 0
         beg: cyl 1023/ head 254/ sector 63;
         end: cyl 1023/ head 254/ sector 63
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

What I do wrong?