2nd-init recovery can't mount sdcard

check /dev/block/mmcblk0 has exists
if not exists
# cd /dev/block/
# mknod mmcblk0 b 179 0
# mknod mmcblk0p1 b 179 1


reference:http://forum.cyanogenmod.com/topic/33179-problems-installing-71-recovery-cant-mount-sdcard/