## Overview

This is an official Linux template. It requires an SNMP client.

#### Notes on filesystem (FS) discovery:
- The ext4/3/2 FS reserves space for privileged usage, typically set at 5% by default.
- BTRFS allocates a default of 10% of the volume for its own needs.
- To mitigate potential disasters, FS usage triggers are based on the maximum available space.
  - Utilization formula: `pused = 100 * (used / used + available)`
- The FS utilization chart, derived from graph prototypes, reflects FS reserved space as the difference between used and available space from the total volume.

## Setup

Install snmpd agent on Linux OS, enable SNMPv2.

Make sure access to UCD-SNMP-MIB is allowed from Zabbix server/proxy host, since,
by default, snmpd (for example, in Ubuntu) limits access to basic system information only:

```text
rocommunity public  default    -V systemonly
```

Ensure snmpd is monitoring disks, using `includeALLDisks` or `disk` options. Example:
```
includeALLDisks 0% # monitors all disks starting with 0% fill rate
# disk / 0% # monitor only / root volume starting with 0% fill rate
```
Make sure you change that in order to read metrics of UCD-SNMP-MIB and UCD-DISKIO-MIB.
Please refer to the documentation: http://www.net-snmp.org/wiki/index.php/Vacm.

You can also try to use `snmpconf`: http://www.net-snmp.org/wiki/index.php/TUT:snmpd_configuration.