Requirements#
Each Node must satisfy the Hardware Requirements and Software Requirements below, while on the contrary, Firewall Ports must be opened only on the Node that hosts the corresponding service. For example, port 6071 (secure access to the Admin Panel) must be opened only on the Node featuring the Carbonio Admin Panel.
Hardware Requirements#
For each node, these are the hardware requirements to comply with. The Disk Space mentioned in the table refers only to the Operating System and not the data (e-mail quota and e-mail traffic, number of documents stored, and so on), because space requirements for the data may vary considerably.
Moreover, you must take into account the following:
The Node that hosts Carbonio Storage and therefore the emails, is the node requiring more disk space.
The Carbonio Files service requires 4GB of RAM to start, so make sure that the node hosting it has at least 6GB of RAM
The Video Recording feature requires additional storage, which is difficult to estimate in advance. Indeed, it depends on a number of factors, including: Number of participants and number of webcam active during the recording; length and dimension of the recording, screen sharing of the recording, and so on. As a general rule, a 1 hour recording at 1280x720 with 25 frames per second would occupy around 400MB of disk space in webm format.
Purely as an example, if you give a quota of 5GB to each of the 150 users, you need to assign 780GB of disk space (30GB for the OS and at 750 for user’s total quota) to the node.
Software Requirements#
Carbonio is available for 64-bit CPUs only and can be installed on top of any of these vanilla distributions:
Ubuntu 20.04 LTS Server Edition
Ubuntu 22.04 LTS Server Edition
RHEL 8 (see specific requirements)
RHEL 9 (see specific requirements) BETA
The following requirements must be satisfied before attempting to install Carbonio.
-
The whole Carbonio infrastructure must have at least one public IP address. The IP address must have a domain name associated, that coincides with the A record in the DNS (e.g.,
A mail.example.com
)Hint
You can check a domain’s A record using the CLI utility
host
:# host -t A mail.example.com
-
To allow the mail server to receive mail, it will be necessary to set up an MX record, which must correspond to the A record (e.g. MX: example.com = mail.example.com )
Hint
You can check a domain’s MX record using the CLI utility
host
:# host -t MX example.com
If either of the
A
orMX
records is not correctly configured, the installation will be temporarily suspended to allow the change of the hostname. Each Node must be able to carry out DNS resolution autonomously and be able to resolve all other Nodes
For improved security of sending emails, you should also define TXT records for SPF, DKIM and DMARC
Python 3, latest version available on the Operating System chosen
Perl, latest version available on the Operating System chosen
Make sure that the
/etc/hosts
does not contain any IPv6 entries
RHEL Specific Requirements#
You need to satisfy these requirements, depending on the RHEL version you want to install:
RHEL 8#
If you plan to install Carbonio on RHEL 8, you need an active subscription to the following repositories, i.e., you must be able to fetch packages from them
-
BaseOS and the other main repositories:
# subscription-manager repos --enable=rhel-8-for-x86_64-baseos-rpms
-
Appstream:
# subscription-manager repos --enable=rhel-8-for-x86_64-appstream-rpms
-
CodeReady:
# subscription-manager repos --enable=codeready-builder-for-rhel-8-x86_64-rpms
-
EPEL:
# dnf -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
SELinux Must be set to disabled or permissive in file
/etc/selinux/config
. You can check the current profile
using the command
# sestatus
If you plan to install Carbonio using Ansible (see Section Prepare the Ansible Environment), the Control Node must be equipped with the following software:
Python 3.12
Latest Ansible version (2.6.9)
Moreover, to connect to the Control Node you must use the
ssh command with the -A
option, e.g.:
$ ssh -A root@mail.example.com
Remember to replace mail.example.com
with the name or IP of the
control node.
RHEL 9 BETA#
If you plan to install Carbonio on RHEL 9, you need an active subscription to the following repositories, i.e., you must be able to fetch packages from them
-
BaseOS and the other main repositories:
# subscription-manager repos --enable=rhel-9-for-x86_64-baseos-rpms
-
Appstream:
# subscription-manager repos --enable=rhel-9-for-x86_64-appstream-rpms
-
CodeReady:
# subscription-manager repos --enable=codeready-builder-for-rhel-9-x86_64-rpms
-
EPEL:
# dnf -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-9.noarch.rpm
SELinux Must be set to disabled or permissive in file
/etc/selinux/config
. You can check the current profile
using the command
# sestatus
If you plan to install Carbonio using Ansible (see Section Prepare the Ansible Environment), the Control Node must be equipped with the following software:
Python 3.12
Latest Ansible version (2.6.9)
Moreover, to connect to the Control Node you must use the
ssh command with the -A
option, e.g.:
$ ssh -A root@mail.example.com
Remember to replace mail.example.com
with the name or IP of the
control node.
systemd
units to replace zmcontrol
By installing Carbonio on RHEL 9 you will no longer be able to manage Carbonio services with the legacy zmcontrol start <service>, zmcontrol restart <service>, and zmcontrol stop <service> commands. Interaction with services should be done exclusively through systemd commands.
Note
The zmcontrol -v command, used to retrieve Carbonio’s configuration, will continue working as usual.
The following are useful commands that can be used to manage the
new systemd
units and find the replacement of the
zmcontrol commands.
-
Get the list of all Carbonio services
# systemctl list-unit-files
-
Check the status of a service, for example Carbonio Tasks
# systemctl status carbonio-tasks.service
To manage a service’s start, stop, and restart, replace
status
in the above command with:start
,stop
, andrestart
respectively.-
zmcontrol start | stop | restart is no longer available and can not be used as a convenience to restart all Carbonio services at once. This command has been replaced by the following four Role-specific
systemd
commands, which must be executed on the Node on which the Role is installed.# systemctl start/stop/restart carbonio-directory-server.target # systemctl start/stop/restart carbonio-appserver.target # systemctl start/stop/restart carbonio-mta.target # systemctl start/stop/restart carbonio-proxy.target
Additional Requirements#
-
Acquaintance with the use of CLI is necessary. All
carbonio
commands must be executed as thezextras
user (these commands will feature azextras$
prompt), while all other commands must be issued as theroot
user, unless stated otherwise.Note
The
zextras
user is created during the Carbonio installation process, it is not necessary to create it beforehand. Give meaningful names to the nodes. For example, call them proxy.example.com, mta.example.com, and so on. Replace
example.com
with your domain name.During the installation procedure, you will need to write down some configuration options and their value, because they will be needed in the setup of the next nodes. These information are summarised at the end of each node’s installation: copy them to a safe place and keep them at hand until the end of the installation. Example of values include: the IP address (public or private) of a node or the password of a database user.
Depending on the Roles installed on each Node, you need to open in your firewall the ports listed in Firewall Ports for all the services you will offer. In case there are problems in the internal network communication, try to disable the firewall and try again: if it works, there was probably some firewall rule preventing communication.
If none of the nodes is exposed to the Internet, you need to forward two ports from the public IP: port 25/smtp to the Node featuring the MTA Role to be able to receive mail, and port 443/https to the node installing the Proxy Role to allow users to access their webmail from a remote location
If you plan to enable other protocols (e.g., POP, IMAP) you should forward also these ports accordingly. You can refer to section Firewall Ports for a list. Do not open these ports if you do not need these protocols!
Also, for security reasons, port 6071, to access the Carbonio Admin Panel should never be exposed on the Internet, but reachable only from a VPN tunnel or similar mechanisms
The same applies for SSH access to the Nodes: it should only be enabled from internal/management networks, while any remote access must be done via VPN tunnel or equivalent mechanism
The hostname of each Node must be a FQDN.
Every Node must be able to resolve all other host names
Firewall Ports#
Carbonio employs SSL/TLS for the communication, and to operate properly, it is necessary to allow network communication on specific ports.
The Nodes should be able to communicate with the other Nodes through a dedicated network. The ports listed in the Internal Connections must be forwarded on all nodes, while those in the External Connections should be forwarded only on the node on which the corresponding Role is installed. For example, port 443 should be forwarded only on the node hosting the Proxy Role.
Furthermore, ports in Internal and External connections are grouped according to the Role that require them, so all ports listed in a table must be forwarded only on the Node on which the Role is installed.
Carbonio requires no specific ports to communicate with the Internet (outgoing traffic), unless you want push notifications to be sent to mobile devices. In this case, the Node installing the Mailstore & Provisioning Role must be able to communicate with the URL https://notifications.zextras.com/firebase/ on port 443.
External Connections#
These ports must be forwarded to the Node installing each Role, to allow communication with remote services on the Internet.
Port |
Protocol |
Service |
---|---|---|
25 |
TCP |
Postfix incoming mail |
465 |
TCP |
Message Submission over TLS protocol |
587 |
TCP |
Port for SMTP autenthicated relay, requires STARTTLS (or opportunistic SSL/TLS) |
Warning
These ports should be exposed only if really needed, and preferably only accessible from a VPN tunnel, if possible, to reduce the attack surface.
Port |
Protocol |
Service |
---|---|---|
80 |
TCP |
unsecured connection to the Carbonio web client |
110 |
TCP |
external POP3 services |
143 |
TCP |
external IMAP services |
443 |
TCP |
secure connection to the Carbonio web client |
993 |
TCP |
external IMAP secure access |
995 |
TCP |
external POP3 secure access |
6071 |
TCP |
secure access to the Admin Panel |
8636 |
TCP |
access to LDAP address books |
5222 |
TCP |
Message Dispatcher, required by the Work Stream Collaboration (Chats) Role |
Warning
The IMAP, POP3, and 6071 ports should be exposed only if really needed, and preferably only accessible from a VPN tunnel, if possible, to reduce the attack surface.
Port |
Protocol |
Service |
---|---|---|
20000-40000 |
UDP |
Client connections for the audio and video streams |
Internal Connections#
Traffic to these ports must be allowed on the Nodes where the corresponding Role is installed, for a proper communication among Carbonio’s internal services.
Port |
Protocol |
Service |
---|---|---|
22 |
TCP |
SSH access |
8301 |
TCP and UDP |
management of Gossip protocol [2] in the LAN |
9100 |
TCP |
Carbonio Monitoring Node exporter |
9256 |
TCP |
Carbonio Monitoring Process exporter |
Port |
Protocol |
Service |
---|---|---|
5432 |
TCP |
Postgres access |
9187 |
TCP |
Postgres data export to Carbonio Monitoring |
Port |
Protocol |
Service |
---|---|---|
389 |
TCP |
unsecure LDAP connection |
636 |
TCP |
secure LDAP connection |
9330 |
TCP |
LDAP data export to Carbonio Monitoring |
Port |
Protocol |
Service |
---|---|---|
25 |
TCP |
Postfix incoming mail |
465 |
TCP |
Message Submission over TLS protocol |
587 |
TCP |
Port for SMTP autenthicated relay, requires STARTTLS (or opportunistic SSL/TLS) |
7026 |
TCP |
bind address of the Milter service |
Port |
Protocol |
Service |
---|---|---|
7025 |
TCP |
local mail exchange using the LMTP protocol |
7071 |
TCP |
Port for SOAP services communication |
7072 |
TCP |
NGINX discovery and authentication |
7073 |
TCP |
SASL discovery and authentication |
7110 |
TCP |
internal POP3 services |
7143 |
TCP |
internal IMAP services |
7993 |
TCP |
internal IMAP secure access |
7995 |
TCP |
internal POP3 secure access |
8080 |
TCP |
internal HTTP services access |
8443 |
TCP |
internal HTTPS services |
8735 |
TCP |
Internal mailbox mailbox communication |
8742 |
TCP |
internal HTTP services, advanced module |
8743 |
TCP |
internal HTTPS services, advanced module |
Port |
Protocol |
Service |
---|---|---|
8188 |
TCP |
Internal connection |
8090 |
TCP |
Servlet communication |
Port |
Protocol |
Service |
---|---|---|
9113 |
TCP |
nginx data export to Carbonio Monitoring |
11211 |
TCP |
memcached access |
Port |
Protocol |
Service |
---|---|---|
8300 |
TCP |
management of incoming requests from other agents |
8302 |
TCP and UDP |
management of Gossip protocol [4] in the WAN |
9107 |
TCP |
Carbonio Mesh data export to Carbonio Monitoring |
21000-21255 |
TCP |
range for registrations ports for sidecar services (automatically assigned) |
The Gossip protocol is an encrypted communication protocol used by Carbonio Mesh for message broadcasting and membership management.