---
name: "pmdazfs"
section: "1"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/pmdazfs"
---

# pmdazfs(1)

ZFS filesystem performance metrics domain agent (PMDA) for Linux

## NAME

**pmdazfs** - ZFS filesystem performance metrics domain agent (PMDA) for Linux

## SYNOPSIS

**$PCP\_PMDAS\_DIR/linux\_zfs/pmdazfs** \[**-D** *debug*\] \[**-d** *domain*\] \[**-l** *logfile*\]

## DESCRIPTION

**pmdazfs** is a Performance Metrics Domain Agent (PMDA) which extracts performance metrics describing the state of the ZFS filesystem from the stats files located in /proc.

The **zfs** PMDA exports metrics that measure information about caching (ARC, L2ARC, ZIL, VDEV), buffering, RAIDZ, dnode operations and pools IO.

A brief description of the **pmdazfs** command line options follows:

- **-d**

  The performance metrics *domain* number must be set to a unique value.

- **-l**

  Location of the log file. By default, a log file named *zfs.log* is written in the current directory of [**pmcd**(1)](/pmcd/1.md) when **pmdazfs** is started, i.e. **$PCP\_LOG\_DIR/pmcd**. If the log file cannot be created or is not writable, output is written to the standard error instead.

## INSTALLATION

OpenZFS is not included in PCP, and has to be installed on the system from the available packages or source. Once OpenZFS is installed and configured, the stats files should appear in /proc and PMDA can be added to PMCD using the Install script:

```
# cd $PCP_PMDAS_DIR/zfs
# ./Install
```

To remove PMDA use the Remove script:

```
# cd $PCP_PMDAS_DIR/zfs
# ./Remove
```

## DEBUGGING OPTIONS

The **-D** or **--debug** option enables the output of additional diagnostics on *stderr* to help triage problems, although the information is sometimes cryptic and primarily intended to provide guidance for developers rather than for end-users. *debug* is a comma separated list of debugging options; use [**pmdbg**(1)](/pmdbg/1.md) with the **-l** option to obtain a list of the available debugging options and their meaning.

Debugging options specific to **pmdazfs** are as follows:

| | |
| --- | --- |
| Option | Description |
| appl0 | warn if any of the ZFS stats files cannot be found |

## SEE ALSO

[**PCPIntro**(1)](/PCPIntro/1.md), [**pmcd**(1)](/pmcd/1.md), [**pcp.conf**(5)](/pcp.conf/5.md) and [**pcp.env**(5)](/pcp.env/5.md).