Hello!
I work with TexasInstrumets DM365 processor, ST NAND512R3A2DZA6 
NAND-flash, linux-2.6.18_pro500 from TexasInstrumets SDK and BusyBox 1.18.4.

Usualy I work with NFS filesystem and when I need create standalone 
device I write system on NAND.
My steps for writing system on NAND:
1. create filesystem
~ # ./flash_eraseall /dev/mtd3
Erasing 16 Kibyte @ 1ffc000 -- 99 % complete.
2. mount filesystem
~ # mount -t yaffs /dev/mtdblock3 /mnt
yaffs: dev is 32505859 name is "mtdblock3"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.3, "mtdblock3"
yaffs_read_super: isCheckpointed 0
3. unpack system
~ # cd /mnt && tar xf /root/system.tar
4. check
/mnt # ls -F /mnt
bin/        home/       lost+found/ proc/       sys/        var/
dev/        lib/        mnt/        root/       tmp/
etc/        linuxrc@    opt/        sbin/       usr/

Usually I umount /dev/mtdblock3 and reboot device, but I found little 
problem - some files is truncated after umount.
As sample, before umount:
~ # wc -cmlw /etc/init.d/modules.sh
        67       180      1467      1467 /etc/init.d/modules.sh
~ # wc -cmlw /mnt/etc/init.d/modules.sh
        67       180      1467      1467 /mnt/etc/init.d/modules.sh

~ # umount /mnt
save exit: isCheckpointed 0
save exit: isCheckpointed 0
~ # mount -t yaffs /dev/mtdblock3 /mnt
yaffs: dev is 32505859 name is "mtdblock3"
yaffs: passed flags ""
yaffs: Attempting MTD mount on 31.3, "mtdblock3"
yaffs_read_super: isCheckpointed 0

After mount:
~ # wc -cmlw /etc/init.d/modules.sh
        67       180      1467      1467 /etc/init.d/modules.sh
~ # wc -cmlw /mnt/etc/init.d/modules.sh
        31       115      1024      1024 /mnt/etc/init.d/modules.sh

As you can see file is truncated and not work.

How can I solve and diagnostic this problem?

Thank you and excuse me for my bad english.

-- 
Best regards,
Brilliantov Kirill Vladimirovich