I have below problem:

root@UBUNTU-32bit:~# chown -v lfs /mnt/lfs/tools
ownership of `/mnt/lfs/tools' retained as lfs
root@UBUNTU-32bit:~# chown -v lfs /mnt/lfs/tools/build
ownership of `/mnt/lfs/tools/build' retained as lfs
root@UBUNTU-32bit:~# chown -v lfs /mnt/lfs/tools/build
ownership of `/mnt/lfs/tools/build' retained as lfs
root@UBUNTU-32bit:~# su - lfs
lfs@UBUNTU-32bit:~$ cd /mnt/lfs/tools
bash: cd: /mnt/lfs/tools: Permission denied
lfs@UBUNTU-32bit:~$ cd /mnt/lfs/tools/build
bash: cd: /mnt/lfs/tools/build: Permission denied
lfs@UBUNTU-32bit:~$

why I haven't permission ?!!!!

What is the filesystem used that is mounted on /mnt/lfs/? Is it mounted read only, or a foreign filesystem such as fat32? If the filesystem is corrupt, the kernel will change access to read only to prevent further corruption.

What does `ls -d /mnt/lfs/ /mnt/lfs/tools' show for the ownership and permissions? If root is denied x access to /mnt/lfs/ then it can't enter to change /mnt/lfs/tools/.

file system is : /dev/sdb1 Type: ext4 mount point : /mnt/lfs

and
root@UBUNTU-32bit:/home/user# ls -d /mnt/lfs/ /mnt/lfs/tools
/mnt/lfs/ /mnt/lfs/tools
root@UBUNTU-32bit:/home/user#

I change mount point of this file system manually in fstab ( I add this new partition to fstab) and change /etc/mtab file from

"/dev/sdb1 /media/new Volume\040Volume ext4 rw,nosuid,nodev,uhelper=udisks 0 0
gvfs-fuse-daemon /root/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev 0 0
/dev/sdb1 /mnt/lfs ext4 rw 0 0" to " /dev/sdb1 /mnt/lfs\040Volume ext4 rw,nosuid,nodev,uhelper=udisks 0 0
gvfs-fuse-daemon /root/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev 0 0
/dev/sdb1 /mnt/lfs ext4 rw 0 0"

maybe problem is from these changes !!!!!

Sorry, use `ls -ld' for the long listing.

Also use the `mount' command to list how the partition is mounted. Or check /etc/mtab.

You don't edit mtab. It is updated by the kernel to list how filesystems are mounted.

root@UBUNTU-32bit:/# ls -ld /mnt/lfs/ /mnt/lfs/tools
drwx------ 3 user user 4096 Aug 13 11:57 /mnt/lfs/
drwxr-xr-x 5 lfs root 4096 Aug 13 14:15 /mnt/lfs/tools
root@UBUNTU-32bit:/#


root@UBUNTU-32bit:/etc# mount
/dev/sda1 on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
gvfs-fuse-daemon on /home/user/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=user)
gvfs-fuse-daemon on /root/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev)
/dev/sdb1 on /mnt/lfs type ext4 (rw)
root@UBUNTU-32bit:/etc#

The owner of /mnt/lfs/tools is already lfs.
The verbose option is simply telling you there was no change.

The owner:group of /mnt/lfs is user:user. The permissions are rwx------. So the lfs user can't enter lfs.

You might want to change the owner of the mount point to lfs as well, and the permissions too

thank you every body for good replies