[comment]: # translation:outdated

[comment]: # ({02b10f8d-02b10f8d})
# 2 Requirements

[comment]: # ({/02b10f8d-02b10f8d})

[comment]: # ({80330f65-80330f65})
#### Hardware

[comment]: # ({/80330f65-80330f65})

[comment]: # ({afccaf51-afccaf51})
##### Memory

Zabbix requires both physical and disk memory. 128 MB of physical memory
and 256 MB of free disk space could be a good starting point. However,
the amount of required disk memory obviously depends on the number of
hosts and parameters that are being monitored. If you're planning to
keep a long history of monitored parameters, you should be thinking of
at least a couple of gigabytes to have enough space to store the history
in the database. Each Zabbix daemon process requires several connections
to a database server. Amount of memory allocated for the connection
depends on configuration of the database engine. 

::: noteclassic
The more
physical memory you have, the faster the database (and therefore Zabbix)
works! 
:::

[comment]: # ({/afccaf51-afccaf51})

[comment]: # ({7967309a-7967309a})
##### CPU

Zabbix and especially Zabbix database may require significant CPU
resources depending on number of monitored parameters and chosen
database engine.

[comment]: # ({/7967309a-7967309a})

[comment]: # ({1cbee7bf-1cbee7bf})
##### Other hardware

A serial communication port and a serial GSM modem are required for
using SMS notification support in Zabbix. USB-to-serial converter will
also work.

[comment]: # ({/1cbee7bf-1cbee7bf})

[comment]: # ({3ccca3da-4ce92ee0})
##### Examples of hardware configuration

The table provides several examples of hardware configurations:

|Name|Platform|CPU/Memory|Database|Monitored hosts|
|----|--------|----------|--------|---------------|
|*Small*|CentOS|Virtual Appliance|MySQL InnoDB|100|
|*Medium*|CentOS|2 CPU cores/2GB|MySQL InnoDB|500|
|*Large*|RedHat Enterprise Linux|4 CPU cores/8GB|RAID10 MySQL InnoDB or PostgreSQL|>1000|
|*Very large*|RedHat Enterprise Linux|8 CPU cores/16GB|Fast RAID10 MySQL InnoDB or PostgreSQL|>10000|

::: noteclassic
Actual configuration depends on the number of active items
and refresh rates very much. It is highly recommended to run the
database on a separate box for large installations.
:::

[comment]: # ({/3ccca3da-4ce92ee0})

[comment]: # ({6737af25-6737af25})
#### Supported platforms

Due to security requirements and mission-critical nature of monitoring
server, UNIX is the only operating system that can consistently deliver
the necessary performance, fault tolerance and resilience. Zabbix
operates on market leading versions.

Zabbix is tested on the following platforms:

-   Linux
-   IBM AIX
-   FreeBSD
-   NetBSD
-   OpenBSD
-   HP-UX
-   Mac OS X
-   Solaris
-   Windows: all desktop and server versions since XP (Zabbix agent
    only)

::: noteclassic
Zabbix may work on other Unix-like operating systems as
well.
:::

::: noteimportant
Zabbix disables core dumps if compiled with
encryption and does not start if system does not allow disabling of core
dumps.
:::

[comment]: # ({/6737af25-6737af25})

[comment]: # ({96bb3570-96bb3570})
#### Software

Zabbix is built around a modern Apache web server, leading database
engines, and PHP scripting language.

[comment]: # ({/96bb3570-96bb3570})

[comment]: # ({e4b953e5-91bb69cb})
##### Database management system

|Software|Version|Comments|
|--------|-------|--------|
|*MySQL*|5.0.3 - 8.0.x|Required if MySQL is used as Zabbix backend database. InnoDB engine is required.<br>MariaDB also works with Zabbix.|
|*Oracle*|10g or later|Required if Oracle is used as Zabbix backend database.|
|*PostgreSQL*|8.1 or later|Required if PostgreSQL is used as Zabbix backend database.<br>It is suggested to use at least PostgreSQL 8.3, which [introduced much better VACUUM performance](http://www.postgresql.org/docs/8.3/static/release-8-3.html).|
|*IBM DB2*|9.7 or later|Required if IBM DB2 is used as Zabbix backend database.|
|*SQLite*|3.3.5 or later|SQLite is only supported with Zabbix proxies. Required if SQLite is used as Zabbix proxy database.|

::: noteimportant
IBM DB2 support is experimental!
:::

[comment]: # ({/e4b953e5-91bb69cb})

[comment]: # ({9044a7d6-0fc7f3dd})
##### Frontend

The following software is required to run Zabbix frontend:

|Software|Version|Comments|
|--------|-------|--------|
|*Apache*|1.3.12 or later|<|
|*PHP*|5.4.0 or later|<|
|PHP extensions:|<|<|
|*gd*|2.0 or later|PHP GD extension must support PNG images (*--with-png-dir*), JPEG (*--with-jpeg-dir*) images and FreeType 2 (*--with-freetype-dir*).|
|*bcmath*|<|php-bcmath (*--enable-bcmath*)|
|*ctype*|<|php-ctype (*--enable-ctype*)|
|*libXML*|2.6.15 or later|php-xml or php5-dom, if provided as a separate package by the distributor.|
|*xmlreader*|<|php-xmlreader, if provided as a separate package by the distributor.|
|*xmlwriter*|<|php-xmlwriter, if provided as a separate package by the distributor.|
|*session*|<|php-session, if provided as a separate package by the distributor.|
|*sockets*|<|php-net-socket (*--enable-sockets*). Required for user script support.|
|*mbstring*|<|php-mbstring (*--enable-mbstring*)|
|*gettext*|<|php-gettext (*--with-gettext*). Required for translations to work.|
|*ldap*|<|php-ldap. Required only if LDAP authentication is used in the frontend.|
|*ibm\_db2*|<|Required if IBM DB2 is used as Zabbix backend database.|
|*mysqli*|<|Required if MySQL is used as Zabbix backend database.|
|*oci8*|<|Required if Oracle is used as Zabbix backend database.|
|*pgsql*|<|Required if PostgreSQL is used as Zabbix backend database.|

::: noteclassic
Zabbix may work on previous versions of Apache, MySQL,
Oracle, and PostgreSQL as well.
:::

::: noteimportant
For other fonts than the default DejaVu, PHP
function
[imagerotate](http://php.net/manual/en/function.imagerotate.php) might
be required. If it is missing, these fonts might be rendered incorrectly
when a graph is displayed. This function is only available if PHP is
compiled with bundled GD, which is not the case in Debian and other
distributions.
:::

[comment]: # ({/9044a7d6-0fc7f3dd})

[comment]: # ({19ce8882-8badded2})
##### Web browser on client side

Cookies and Java Script must be enabled.

Latest versions of Google Chrome, Mozilla Firefox, Microsoft Internet
Explorer and Opera are supported. Other browsers (Apple Safari,
Konqueror) may work with Zabbix as well.

::: notewarning
The same origin policy for IFrames is implemented,
which means that Zabbix cannot be placed in frames on a different
domain.\
\
Still, pages placed into a Zabbix frame will have access to Zabbix
frontend (through JavaScript) if the page that is placed in the frame
and Zabbix frontend are on the same domain. A page like
`http://secure-zabbix.com/cms/page.html`, if placed into screens or
dashboards on `http://secure-zabbix.com/zabbix/`, will have full JS
access to Zabbix.
:::

[comment]: # ({/19ce8882-8badded2})

[comment]: # ({f7e2cd50-2478f726})
##### Server

Mandatory requirements are needed always. Optional requirements are
needed for the support of the specific function.

|Requirement|Status|Description|
|-----------|------|-----------|
|*libpcre*|Mandatory|PCRE library is required for [Perl Compatible Regular Expression](https://en.wikipedia.org/wiki/Perl_Compatible_Regular_Expressions) (PCRE) support.<br>The naming may differ depending on the GNU/Linux distribution, for example 'libpcre3' or 'libpcre1'. Note that you need exactly PCRE (v8.x); PCRE2 (v10.x) library is not used.|
|*libevent*|^|Required for bulk metric support and IPMI monitoring. Version 1.4 or higher.<br>Note that for Zabbix proxy this requirement is optional; it is needed for IPMI monitoring support.|
|*libpthread*|^|Required for mutex and read-write lock support.|
|*zlib*|^|Required for compression support.|
|*OpenIPMI*|Optional|Required for IPMI support.|
|*libssh2*|^|Required for SSH support. Version 1.0 or higher.|
|*fping*|^|Required for [ICMP ping items](/manual/config/items/itemtypes/simple_checks#icmp_pings).|
|*libcurl*|^|Required for web monitoring, VMware monitoring and SMTP authentication. For SMTP authentication, version 7.20.0 or higher is required. Also required for Elasticsearch.|
|*libiksemel*|^|Required for Jabber support.|
|*libxml2*|^|Required for VMware monitoring.|
|*net-snmp*|^|Required for SNMP support.|

[comment]: # ({/f7e2cd50-2478f726})

[comment]: # ({a182cd3a-17c16f91})
##### Java gateway

If you obtained Zabbix from the source repository or an archive, then
the necessary dependencies are already included in the source tree.

If you obtained Zabbix from your distribution's package, then the
necessary dependencies are already provided by the packaging system.

In both cases above, the software is ready to be used and no additional
downloads are necessary.

If, however, you wish to provide your versions of these dependencies
(for instance, if you are preparing a package for some Linux
distribution), below is the list of library versions that Java gateway
is known to work with. Zabbix may work with other versions of these
libraries, too.

The following table lists JAR files that are currently bundled with Java
gateway in the original code:

|Library|License|Website|Comments|
|-------|-------|-------|--------|
|*logback-core-0.9.27.jar*|EPL 1.0, LGPL 2.1|<http://logback.qos.ch/>|Tested with 0.9.27, 1.0.13, and 1.1.1.|
|*logback-classic-0.9.27.jar*|EPL 1.0, LGPL 2.1|<http://logback.qos.ch/>|Tested with 0.9.27, 1.0.13, and 1.1.1.|
|*slf4j-api-1.6.1.jar*|MIT License|<http://www.slf4j.org/>|Tested with 1.6.1, 1.6.6, and 1.7.6.|
|*android-json-4.3\_r3.1.jar*|Apache License 2.0|<https://android.googlesource.com/platform/libcore/+/master/json>|Tested with 2.3.3\_r1.1 and 4.3\_r3.1. See src/zabbix\_java/lib/README for instructions on creating a JAR file.|

Java gateway compiles and runs with Java 1.6 and above. It is
recommended that those who provide a precompiled version of the gateway
for others use Java 1.6 for compilation, so that it runs on all versions
of Java up to the latest one.

[comment]: # ({/a182cd3a-17c16f91})

[comment]: # ({bd4496d0-ed39a6fd})
#### Database size

Zabbix configuration data require a fixed amount of disk space and do
not grow much.

Zabbix database size mainly depends on these variables, which define the
amount of stored historical data:

-   Number of processed values per second

This is the average number of new values Zabbix server receives every
second. For example, if we have 3000 items for monitoring with refresh
rate of 60 seconds, the number of values per second is calculated as
3000/60 = **50**.

It means that 50 new values are added to Zabbix database every second.

-   Housekeeper settings for history

Zabbix keeps values for a fixed period of time, normally several weeks
or months. Each new value requires a certain amount of disk space for
data and index.

So, if we would like to keep 30 days of history and we receive 50 values
per second, total number of values will be around (**30**\*24\*3600)\*
**50** = 129.600.000, or about 130M of values.

Depending on the database engine used, type of received values (floats,
integers, strings, log files, etc), the disk space for keeping a single
value may vary from 40 bytes to hundreds of bytes. Normally it is around
90 bytes per value for numeric items^**2**^. In our case, it means that
130M of values will require 130M \* 90 bytes = **10.9GB** of disk space.

::: noteclassic
The size of text/log item values is impossible to predict
exactly, but you may expect around 500 bytes per value.
:::

-   Housekeeper setting for trends

Zabbix keeps a 1-hour max/min/avg/count set of values for each item in
the table **trends**. The data is used for trending and long period
graphs. The one hour period can not be customised.

Zabbix database, depending on database type, requires about 90 bytes per
each total. Suppose we would like to keep trend data for 5 years. Values
for 3000 items will require 3000\*24\*365\* **90** = **2.2GB** per year,
or **11GB** for 5 years.

-   Housekeeper settings for events

Each Zabbix event requires approximately 250 bytes of disk space^**1**^.
It is hard to estimate the number of events generated by Zabbix daily.
In the worst case scenario, we may assume that Zabbix generates one
event per second.

For each recovered event an event\_recovery record is created. Normally
most of events will be recovered so we can assume one event\_recovery
record per event. That means additional 80 bytes per event.

Optionally events can have tags, each tag record requiring approximately
100 bytes of disk space^**1**^. The number of tags per event (\#tags)
depends on configuration. So each will need an additional \#tags \* 100
bytes of disk space.

It means that if we want to keep 3 years of events, this would require
3\*365\*24\*3600\* (250+80+\#tags\*100) = **\~30GB**+\#tags\*100B disk
space^**2**^.

::: noteclassic
 ^**1**^ More when having non-ASCII event names, tags and
values.

^**2**^ The size approximations are based on MySQL and might be
different for other databases. 
:::

The table contains formulas that can be used to calculate the disk space
required for Zabbix system:

|Parameter|Formula for required disk space (in bytes)|
|---------|------------------------------------------|
|*Zabbix configuration*|Fixed size. Normally 10MB or less.|
|*History*|days\*(items/refresh rate)\*24\*3600\*bytes<br>items : number of items<br>days : number of days to keep history<br>refresh rate : average refresh rate of items<br>bytes : number of bytes required to keep single value, depends on database engine, normally \~90 bytes.|
|*Trends*|days\*(items/3600)\*24\*3600\*bytes<br>items : number of items<br>days : number of days to keep history<br>bytes : number of bytes required to keep single trend, depends on database engine, normally \~90 bytes.|
|*Events*|days\*events\*24\*3600\*bytes<br>events : number of event per second. One (1) event per second in worst case scenario.<br>days : number of days to keep history<br>bytes : number of bytes required to keep single trend, depends on database engine, normally \~330 + average number of tags per event \* 100 bytes.|

So, the total required disk space can be calculated as:\
**Configuration + History + Trends + Events**\
The disk space will NOT be used immediately after Zabbix installation.
Database size will grow then it will stop growing at some point, which
depends on housekeeper settings.

[comment]: # ({/bd4496d0-ed39a6fd})

[comment]: # ({new-4f7af4f4})

#### Default port numbers

The following table lists default port numbers that Zabbix components listen on:

|Zabbix component|Port number|Protocol|Type of connection|
|-------|-------|-------|-------|
|Zabbix agent|10050|TCP|on demand|
|Zabbix server|10051|TCP|on demand|
|Zabbix proxy|10051|TCP|on demand|
|Zabbix Java gateway|10052|TCP|on demand|

[comment]: # ({/new-4f7af4f4})

[comment]: # ({c021ddce-2bb40d7c})
#### Time synchronisation

It is very important to have precise system date on server with Zabbix
running. [ntpd](http://www.ntp.org/) is the most popular daemon that
synchronizes the host's time with the time of other machines. It's
strongly recommended to maintain synchronised system date on all systems
Zabbix components are running on.

If the time is not synchronised Zabbix will convert timestamps of the
gathered data into Zabbix server time by taking client/server timestamps
after establishing data connection and adjusting the received item value
timestamps by the client-server time difference. To keep it simple and
avoid possible complications the connection latency is ignored. Because
of that the connection latency is added to the timestamps of data
acquired from active connections (active agent, active proxy, sender)
and subtracted from the timestamps of data acquired from passive
connections (passive proxy). All other checks are done in server time
and their timestamps are not adjusted.

[comment]: # ({/c021ddce-2bb40d7c})

[comment]: # ({1cac681a-1cac681a})
#### Time synchronization

It is very important to have precise system time on server with Zabbix
running. [ntpd](http://www.ntp.org/) is the most popular daemon that
synchronizes the host's time with the time of other machines. It's
strongly recommended to maintain synchronized system time on all systems
Zabbix components are running on.

[comment]: # ({/1cac681a-1cac681a})