You can test if pear is available on your server by running 'which pear'
Make sure /usr/local/bin/pear exists on your server and its permission is 755. Run this command to reset the permission.
chmod 755 /usr/local/bin/pear
If the file does not exist, you will need to recompile PHP using WHM easyapache. Make sure PEAR is enabled (it is enabled by default).