Hi, I utilized yaffs2 to K9F2G08(1Page=2K+64Bytes), the kernel was linux2.6.12. All seemed OK except the command, umount, was executed, the used space would be increased, each time, when a umount command followed by the mount command. What's wrong with it. The following was the infoes. Thanks! [root@INTUM /]$mount /dev/mtdblock/5 on /mnt/database type yaffs2 (rw,noatime) [root@INTUM /]$df Filesystem 1k-blocks Used Available Use% Mounted on /dev/mtdblock/5 208896 1292 207604 1% /mnt/database //the used space was 1292K [root@INTUM /]$umount /mnt/database/ save exit: isCheckpointed 1 [root@INTUM /]$mount -t yaffs2 /dev/mtdblock/5 /mnt/database/ yaffs: dev is 32505861 name is "mtdblock5" yaffs: passed flags "" yaffs: Attempting MTD mount on 31.5, "mtdblock5" [root@INTUM /]$df Filesystem 1k-blocks Used Available Use% Mounted on /dev/mtdblock/5 208896 1420 207476 1% /mnt/database //the used space increased to 1420K