Pogoplug E02 booting from ext3 stick

I have a pogoplug E02. I want to boot from a ext3. I changed

usb_rootfstype=ext3

with fw_setenv and in /etc/fstab,

/dev/root      /               ext3    defaults 0 1

The kernel log showed ok booting

U-Boot 2011.12 (Feb 20 2012 - 21:21:59)
Pogoplug E02
arm-none-linux-gnueabi-gcc (Sourcery G++ Lite 2009q3-67) 4.4.1
GNU ld (Sourcery G++ Lite 2009q3-67) 2.19.51.20090709
Hit any key to stop autoboot:  0
(Re)start USB...
USB:   Register 10011 NbrPorts 1
USB EHCI 1.00
scanning bus for devices... 3 USB Device(s) found
       scanning bus for storage devices... 1 Storage Device(s) found
Loading file "/rescueme" from usb device 0:1 (usbda1)
** File not found /rescueme
reading /rescueme.txt

** Unable to read "/rescueme.txt" from usb 0:1 **
Creating 1 MTD partitions on "nand0":
0x000002500000-0x000008000000 : "mtd=3"
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size:   131072 bytes (128 KiB)
UBI: logical eraseblock size:    129024 bytes
UBI: smallest flash I/O unit:    2048
UBI: sub-page size:              512
UBI: VID header offset:          512 (aligned 512)
UBI: data offset:                2048
UBI: attached mtd1 to ubi0
UBI: MTD device name:            "mtd=3"
UBI: MTD device size:            91 MiB
UBI: number of good PEBs:        726
UBI: number of bad PEBs:         2
UBI: max. allowed volumes:       128
UBI: wear-leveling threshold:    4096
UBI: number of internal volumes: 1
UBI: number of user volumes:     0
UBI: available PEBs:             715
UBI: total number of reserved PEBs: 11
UBI: number of PEBs reserved for bad PEB handling: 7
UBI: max/mean erase counter: 1/1
UBIFS error (pid 0): ubifs_get_sb: cannot open "ubi:rootfs", error -19
Error reading superblock on volume 'ubi:rootfs'!
Loading file "/boot/uImage" from usb device 0:1 (usbda1)
1 bytes read
Found bootable drive on usb 0:1
Loading file "/boot/uImage" from usb device 0:1 (usbda1)
2010224 bytes read
Loading file "/boot/uInitrd" from usb device 0:1 (usbda1)
6514910 bytes read
## Booting kernel from Legacy Image at 00800000 ...
   Image Name:   Linux-3.9.11-kirkwood-tld-1
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    2010160 Bytes = 1.9 MiB
   Load Address: 00008000
   Entry Point:  00008000
   Verifying Checksum ... OK
## Loading init Ramdisk from Legacy Image at 01100000 ...
   Image Name:   initramfs-3.9.11-kirkwood-tld-1
   Image Type:   ARM Linux RAMDisk Image (gzip compressed)
   Data Size:    6514846 Bytes = 6.2 MiB
   Load Address: 00000000
   Entry Point:  00000000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
OK

But I can't access it by ssh.

Does anyone know something wrong with this set up.