Frank wrote:
Recently I have noticed that calling up a terminal using Sudo from a
menu..i.e. sudo /usr/bin/rxvt sometimes results in a 4 to 5 second
delay before the terminal opens up. At other times it's
instantaneous.
It happens whether the command is run from my launcher Wbar, or the
IceWm menu. Does anyone know what's going on ?
It is the fqdn flag which is on by default. I always turn this off.
Otherwise running sudo commands is serialized behind looking up
hostnames. Looking up hostnames is an external activity and puts a
dependency upon network connectivity. It can be slow.
The sudoers man page (man 5 sudoers) says:
fqdn Set this flag if you want to put fully qualified host
names in the sudoers file. I.e., instead of myhost you
would use myhost.mydomain.edu. You may still use the
short form if you wish (and even mix the two). Beware
that turning on fqdn requires sudo to make DNS lookups
which may make sudo unusable if DNS stops working (for
example if the machine is not plugged into the
network). Also note that you must use the host's
official name as DNS knows it. That is, you may not
use a host alias (CNAME entry) due to performance
issues and the fact that there is no way to get all
aliases from DNS. If your machine's host name (as
returned by the hostname command) is already fully
qualified you shouldn't need to set fqdn. This flag is
on by default.
The best fix depends upon the version of sudo (version of Debian)
available to you. As of Debian version 1.7.2p1-1 (available in
Squeeze) the default /etc/suders file created on installation contains
an "#includedir" directive to load files from /etc/sudoers.d/ but that
is not automatically configured upon an upgrade. I recommend
configurating it and then using a local unique file there. It avoids
needing to modify the /etc/sudoers file and therefore allows the
package to automatically upgrade that file with new defaults upon
package upgrades.
In any case to turn off fqdn simply add !fqdn to your sudoers Default
line or add a new line.
Defaults !fqdn