I was going to use wget to download a Hadoop tarball, but got the error below:
[root@linyuhe mnt]# wget http://mirror.cnop.net/nagios/nagios-plugins-1.4.14.tar.gz
-bash: /usr/bin/wget: Permission denied
A permission error even for the root account? That’s a first for me.
Check wget’s permission list:
[root@linyuhe bin]# ls -l wget
-rw-r–r– 1 root root 364072 Feb 11 2014 wget
No execute (x) bit. So I tried adding execute permission for the root account:
[root@linyuhe mnt]# chmod +x /usr/bin/wget
chmod: changing permissions of `/usr/bin/wget': Operation not permitted
Ugh, no chmod permission either.
Then came a bunch of googling……
Turns out an immutable attribute had been set on the file:
[root@linyuhe bin]# lsattr wget
—-i——–e- wget
Remove the immutable (i) attribute:
[root@linyuhe bin]# chattr -i wget
Then add execute permission for root:
[root@linyuhe mnt]# chmod +x /usr/bin/wget
Now run the wget command again:

It works now.