Installing ClamAV on a server

Created on 2023/03/06

This article explains how to install ClamAV software, to be used in conjunction with Cells Flows job for antivirus scan.

From the Clam AV website:

Clam AntiVirus is an open source (GPLv2) anti-virus toolkit, designed especially for e-mail scanning on mail gateways. It provides a number of utilities including a flexible and scalable multi-threaded daemon, a command line scanner and advanced tool for automatic database updates. The core of the package is an anti-virus engine available in a form of shared library.

Below information are based on the official installation guide.


Following commands will install:

  • clamav: the antivirus and also the client to scan.
  • clamav-daemon: installs the daemon that can be used with TCP or UNIX and allow scanning.
  • clamav-freshclam: this package handles all the updates for the antivirus database.
sudo apt install clamav clamav-daemon clamav-freshclam


After you have installed all the packages, run this command to configure clamav-daemon. You can keep default settings for almost everything, see details below for the parameters that have to be set explicitly.

sudo dpkg-reconfigure clamav-daemon

Important settings:

  • Socket: choose local UNIX socket if both Cells and ClamAV run on the same machine, in such case, you should remember the path to the socket file (typically: /var/run/clamav/clamd.ctl). You can choose TCP otherwise, and note FQDN and port used.
  • Group Owner of the socket: choose pydio (or the user that runs the cells process if you did not follow our recommendations during Cells install)
  • Maximum stream length: if you want clamd to scan bigger files, put a larger value than the 25MB default. Warning: this will also consume more resources.
  • Choose pydio / pydio as user & group for the daemon process

The daemon is started with systemd, at this point, the service should be started and enabled, to double check:

sudo systemctl status clamav-daemon