Почему показанный команду не может вступить в силу?

 chown -Rf www-data.www-data /var/www/html/test/
 ls -l  /var/www/html/test
total 192
-rwxr-xr-x  1 root root   418 Mar 17 21:31 index.php
-rwxr-xr-x  1 root root 19930 Mar 17 21:31 license.txt
-rwxr-xr-x  1 root root  7360 Mar 17 21:31 readme.html
-rwxr-xr-x  1 root root  5035 Mar 17 21:31 wp-activate.php
drwxr-xr-x  9 root root  8192 Mar 17 21:31 wp-admin
-rwxr-xr-x  1 root root   271 Mar 17 21:31 wp-blog-header.php
-rwxr-xr-x  1 root root  1369 Mar 17 21:31 wp-comments-post.php
-rwxr-xr-x  1 root root  2866 Mar 17 22:10 wp-config.php
-rwxr-xr-x  1 root root  2853 Mar 17 21:31 wp-config-sample.php
drwxr-xr-x  6 root root  4096 Mar 17 21:31 wp-content
-rwxr-xr-x  1 root root  3286 Mar 17 21:31 wp-cron.php
drwxr-xr-x 16 root root 16384 Mar 17 21:31 wp-includes
-rwxr-xr-x  1 root root  2380 Mar 17 21:31 wp-links-opml.php
-rwxr-xr-x  1 root root  3316 Mar 17 21:31 wp-load.php
-rwxr-xr-x  1 root root 33770 Mar 17 21:31 wp-login.php
-rwxr-xr-x  1 root root  7887 Mar 17 21:31 wp-mail.php
-rwxr-xr-x  1 root root 13021 Mar 17 21:31 wp-settings.php
-rwxr-xr-x  1 root root 28594 Mar 17 21:31 wp-signup.php
-rwxr-xr-x  1 root root  4035 Mar 17 21:31 wp-trackback.php
-rwxr-xr-x  1 root root  3061 Mar 17 21:31 xmlrpc.php

 df   /var/www/html/test
Filesystem     1K-blocks  Used Available Use% Mounted on
/dev/sda7        4869120 56812   4812308   2% /var/www/html
 blkid 
 #some info ommitted
/dev/sda7: UUID="   " TYPE="vfat" PARTUUID="   "
sudo chown -R  www-data.www-data /var/www/html/test/
chown: changing ownership of ‘/var/www/html/test/’: Operation not permitted
cat /etc/fstab
# /var/www/html was on /dev/sda7 during installation
UUID=3E3D-09A6  /var/www/html  vfat   defaults  0    0

id
uid=0(root) gid=0(root) groups=0(root)

mount
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=10240k,nr_inodes=488907,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,relatime,size=785640k,mode=755)
/dev/sda3 on / type ext4 (rw,relatime,errors=remount-ro,data=ordered)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
tmpfs on /sys/fs/cgroup type tmpfs (ro,nosuid,nodev,noexec,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=23,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
mqueue on /dev/mqueue type mqueue (rw,relatime)
/dev/sda7 on /var/www/html type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro)
/dev/sda6 on /win7_d type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=utf8,shortname=mixed,utf8,errors=remount-ro)
/dev/sda1 on /win7_c type fuseblk (rw,relatime,user_id=0,group_id=0,allow_other,blksize=4096)
/dev/sda2 on /home type ext4 (rw,relatime,data=ordered)
rpc_pipefs on /run/rpc_pipefs type rpc_pipefs (rw,relatime)
tmpfs on /run/user/109 type tmpfs (rw,nosuid,nodev,relatime,size=392820k,mode=700,uid=109,gid=118)
tmpfs on /run/user/1000 type tmpfs (rw,nosuid,nodev,relatime,size=392820k,mode=700,uid=1000,gid=1000)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse (rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)

Это настолько странно для факта, я - пользователь root, почему никакое разрешение? Почему показанный команду не может вступить в силу?
Как зафиксировать его?