[Techtalk] remote testing of automount service
alwanza at oz.net
Wed Oct 29 06:26:30 UTC 2008
I'm the Linux Sys Admin responsible for 32 linux workstations that all get
their home directories from a Linux file server, through the automount
service. I have root authority on all.
I've written a script that I run through cron that pings the workstations
and makes sure they are powered on and connected to the network. It pages
me when there is a problem. I used perl and Net::Ping to create this script
so it doesn't hang when ping isn't responding.
I wish I could do similar for automount. The problem is that if automount
(autofs) is NOT running, then ssh hangs forever. The reason ssh hangs is
because I closed off the opportunity to ssh as root (for security purposes)
and if I ssh using my automounted user login and automount isn't running,
then ssh can't find my ssh keyfile and it hangs asking for a password.
I've written scripts that check ssh, automount, who - and they all work fine
provided I run them on the command line and if they encounter trouble (which
is what they are trying to detect); I kill the script and then test that
host manually. I can do that because each time I start testing a new host,
I print out a line that indicates "Now testing host 'hostname'". If it
hangs, I just kill the script, test that host manually, and rewrite the
input list to eliminate the hosts I've already tested and rerun the script.
Maybe someone on this list knows a trick or switch I can use with ssh so it
will return rather than hang or somehow get around my having to put a plain
text password in a file or maybe there is a Perl module I don't know about
that can do for ssh what Net::Ping does for ping?
Any suggestions along those lines would be very helpful. My users are
writing programs in C++ and compiling them with g++ and some error that new
users make (rarely, but enough that it can be a problem) seems to crash the
automount service, while allowing everything else to run.
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