I was interested in running the Avast anti-virus program on a Linux computer. However, once running I had an Invalid argument error.
The Avast anti-virus program was installed using dpkg, its not available as a linked download on the website.
As root I navigated to my usual downloads directory, cd Downloads
From this directory I downloaded the Avast package:
wget http://files.avast.com/files/linux/avast4workstation_1.3.0-2_i386.deb
The package was then installed using dpkg:
dpkg -i avast4workstation_1.3.0-2_i386.deb
Avast can then be run from the Applications/Utilities menu category of KDE.
After actioning the update, on the GUI interface, an error was encountered An error occurred in avast! engine: Invalid argument
Searching on the Internet I found that this is a generally recognised error. The maximum amount of shared memory allowed has been exceeded. An artificial limitation is imposed which dictates the maximum size of one SHM block. Exceeding this limit causes the error.
To adjust the SHM memory block limitation the value can be adjusted for the currently active computer and for the next time it is booted.
To set the value without rebooting, as root run sysctl -w kernel.shmmax=128000000
To create a permanent configuration, for the next time the computer is booted, as root edit the file /etc/sysctl.conf and add to the end of the file kernel.shmmax = 128000000
