Saturday, January 30, 2010

REBOOTING BECAUSE OF FORK BOMBS

REBOOTING BECAUSE OF FORK BOMBS


There is nothing more frustrating
for an Administrator who has to
reboot system due to fork bomb

(the number of processes in the
system reaches the maximum limit
when a user, even a superuser,
tries to execute some command, the
system will respond with Vfork
failed)

In Solaris under SPARC, this can be
controlled by specifying a line in
/etc/system

set maxuprc=64

And reboot the system. Now a user
can have maximum of 64 processes
under his ownership. By default
the 'maxuprc' value is
16*maxusers - 5 where
'maxusers' is another tunable
parameter in /etc/system

Caution : You should have a backup
of /etc/system file before you make
the changes. So that you can revert
back to old system file using
boot -a option in case of
inconsistent system file.

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