ProxMenux/web/messages/en/docs/post-install/performance.json

{
  "meta": {
    "title": "Post-Install: Performance | ProxMenux Documentation",
    "description": "Performance options in the ProxMenux Customizable post-install script. Replaces single-threaded gzip with pigz (parallel gzip) for faster backups and compression on multi-core hosts."
  },
  "header": {
    "title": "Post-Install: Performance",
    "description": "Performance options inside the Customizable post-install script. Currently this category contains a single optimization: replacing gzip with pigz so backups and compression use every CPU core instead of one.",
    "section": "Settings post-install Proxmox"
  },
  "intro": {
    "title": "What this category covers",
    "body": "The only performance option here rewires the system's gzip to a parallel implementation. Other performance-related tweaks (memory tuning, I/O scheduling, ZFS ARC sizing, kernel limits) live under their own categories (<em>System</em>, <em>Storage</em>) because they affect different subsystems."
  },
  "pigz": {
    "heading": "Use pigz for faster gzip compression",
    "intro": "Standard <code>gzip</code> compresses data using a <strong>single CPU core</strong>. On modern Proxmox hosts with 8, 16 or 32 cores, that is a huge bottleneck during <code>vzdump</code> VM/CT backups, log rotation, and anything else that pipes through <code>gzip</code>. <a>pigz</a> is a drop-in parallel replacement: same gzip-compatible output, but it spreads the work across every core.",
    "doesTitle": "What ProxMenux does",
    "doesIntro": "Four steps, all idempotent:",
    "doesItems": [
      "Sets <code>pigz: 1</code> in <code>/etc/vzdump.conf</code> so Proxmox's backup tool uses pigz natively.",
      "Installs the <code>pigz</code> apt package if not already present.",
      "Writes a wrapper script at <code>/bin/pigzwrapper</code> that forwards every argument to <code>/usr/bin/pigz</code>.",
      "Registers a dpkg diversion for the system's <code>gzip</code> binary (<code>/usr/bin/gzip</code> on Proxmox VE 9, <code>/bin/gzip</code> on Proxmox VE 8): the real binary is kept beside it as <code>gzip.distrib</code> and the wrapper takes its place. From now on, <em>anything</em> that calls <code>gzip</code> — logrotate, <code>tar czf</code>, scripts, vzdump — uses pigz transparently.",
      "Checks that the file kept as <code>gzip.distrib</code> is a working gzip before the wrapper is put in place, and reinstalls the <code>gzip</code> package first when it is not. A host that still has the earlier <code>/bin/gzip.original</code> swap is moved to the diversion when the option is applied again."
    ],
    "replacesTitle": "This replaces a system binary",
    "replacesBody": "Putting a wrapper in the place of <code>gzip</code> is unusual. It is safe (the wrapper produces gzip-compatible output), but worth knowing: scripts that hardcode paths, run inside restrictive chroots, or verify binary hashes may behave differently. The real binary is preserved as <code>gzip.distrib</code>, and because the replacement is a dpkg diversion, an update of the <code>gzip</code> package — or the upgrade from Proxmox VE 8 to 9 — updates that file and leaves the wrapper in place.",
    "revertTitle": "Reversible from the Uninstall menu",
    "revertBody": "This optimization is tracked. <link>Uninstall Optimizations</link> copies the real binary from <code>gzip.distrib</code> back over the wrapper, removes the diversion and the <code>pigzwrapper</code>, comments out the <code>pigz</code> line in <code>/etc/vzdump.conf</code>, and runs <code>apt purge pigz</code> once gzip is verified to work. Manual equivalent on Proxmox VE 9:",
    "verifyTitle": "Verification",
    "verifyBody": "After applying, <code>gzip --version</code> should mention pigz. A quick benchmark also shows the speed difference on a multi-core host:",
    "whenTitle": "When this matters most",
    "whenBody": "The impact scales with <strong>how many cores the host has</strong> and <strong>how often you run backups</strong>. On a 2-core home-lab box with one daily vzdump, the benefit is marginal. On a 16-core production host backing up a dozen VMs every night, pigz can cut the backup window to a fraction of what single-threaded gzip takes."
  },
  "related": {
    "heading": "Related",
    "items": [
      {
        "label": "Backup and Restore commands",
        "href": "/docs/help-info/backup-commands",
        "tailRich": " — vzdump CLI reference, including <code>--pigz</code> threads option."
      },
      {
        "label": "Storage",
        "href": "/docs/post-install/storage",
        "tail": " — vzdump speed limits and ZFS ARC tuning."
      },
      {
        "label": "System",
        "href": "/docs/post-install/system",
        "tail": " — file-descriptor and memory tuning."
      },
      {
        "label": "Customizable Post-Install",
        "href": "/docs/post-install/customizable",
        "tail": " — back to the parent menu."
      }
    ]
  }
}