PMDAZFS(1)

💖 NAME 💖

pmdazfs — bestie, it's the ZFS filesystem performance metrics domain agent (PMDA) for Linux. Yes, the whole thing. Say it with me 🫶

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✨ SYNOPSIS ✨

$PCP_PMDAS_DIR/linux_zfs/pmdazfs [-D debug] [-d domain] [-l logfile]

That's it, that's the whole summoning ritual 🔮

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🌸 DESCRIPTION 🌸

Okay so. pmdazfs is a Performance Metrics Domain Agent (PMDA), and what it does is extract performance metrics describing the state of the ZFS filesystem from the stats files chillin' in /proc. That's the vibe. It just. Reads the files. And tells you everything 🦋

The zfs PMDA exports metrics that measure info about caching (ARC, L2ARC, ZIL, VDEV), buffering, RAIDZ, dnode operations and pools IO. So like, every little thing your ZFS is doing? It knows. Main character energy fr fr 👑

A brief description of the pmdazfs command line options follows — and yes bestie I'm giving you the full rundown, no skipping:

• -d — The performance metrics domain number must be set to a unique value. Unique!! Not "eh, close enough". Don't be that girl 🙈
• -l — Location of the log file. By default, a log file named zfs.log gets written in the current directory of pmcd(1) when pmdazfs is started, i.e. $PCP_LOG_DIR/pmcd. And if the log file can't be created, or isn't writable? Then output goes to standard error instead. It always has a backup plan, we love a resilient queen 💅

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🎀 INSTALLATION 🎀

So here's the thing. OpenZFS is not included in PCP — it's not just gonna appear, babes 😭 — and it 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 the PMDA can be added to PMCD using the Install script:

# cd $PCP_PMDAS_DIR/zfs
# ./Install

And to remove the PMDA, use the Remove script:

# cd $PCP_PMDAS_DIR/zfs
# ./Remove

Install, remove, slay, repeat 🌈

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🔥 DEBUGGING OPTIONS 🔥

The -D or --debug option enables the output of additional diagnostics on stderr to help triage problems. Ngl though — the information is sometimes cryptic and primarily intended to provide guidance for developers rather than for end-users. So like, it's giving secret dev language 💀

debug is a comma separated list of debugging options; use pmdbg(1) with the -l option to obtain a list of the available debugging options and their meaning. Go get the full menu, bestie 📜

Debugging options specific to pmdazfs are as follows:

• appl0 — warn if any of the ZFS stats files cannot be found. It's the "hey girl, something's missing" alarm 🚨

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🌟 SEE ALSO 🌟

PCPIntro(1), pmcd(1), pcp.conf(5) and pcp.env(5).

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Okay that's the whole page!! This one comes to you from the Performance Co-Pilot (PCP) girlies, and it's pmdazfs(1) — the Linux ZFS PMDA — and if you take one thing away from this, take the Install script. Periodt 💖✨🎀🦋