ZFS/Advanced

Overview

This section delves into advanced topics for ZFS users, encompassing a wide range of sophisticated functionalities and optimization techniques. Users will discover in-depth coverage of automation scripts that streamline routine tasks and system maintenance, along with comprehensive ZFS tuning strategies for maximizing performance across different workload scenarios. The topics include advanced dataset management, custom scripting for monitoring and maintenance, performance optimization through ARC and ZIL tuning, sophisticated backup and restoration procedures, and enterprise-level high availability configurations. Additionally, this section explores advanced encryption methodologies, RAID-Z expansion techniques, special VDEV optimization, and container integration strategies. Whether you're managing a home server or enterprise storage infrastructure, these advanced topics will help you leverage ZFS's full potential through proper system integration, automated maintenance, and performance monitoring. Particular attention is given to real-world scenarios and practical implementations, ensuring that users can effectively apply these advanced concepts to their specific use cases.

Automation Scripts

Abstraction: Manually updating the ZFS kernel module can be a time-consuming and error-prone process that involves:

• Monitoring the OpenZFS GitHub releases page for updates
• Checking kernel compatibility for each new release
• Downloading and installing the appropriate versions
• Ensuring system consistency between the ZFS module and kernel versions

This automation system simplifies these tasks through a set of coordinated scripts that handle the entire update process.

System Requirements: Make sure you have the following prerequisites:

• Linux system with bash shell
• curl installed for downloading release information
• Internet connection to access GitHub
• Sufficient permissions to install kernel modules and updates
• Directory with appropriate write permissions for script operation

compatibility script

This script web-scrapes this page to find the most recent updated ZFS module and the supported kernel version that goes with it. Its functions and data structures are used in another script, which will be explained further down this section.

Note
There are probably some hidden edge cases that I am not aware of. I do know if the DOM tree structure gets changed, this script can break. One way to fix this would be prepending another if statement inside of parse_linux_compatibility, but you have to inspect this to find the right expression. So far: Linux: compatible with ... kernels and Linux kernels ... will get zfs-3.0 all the way down to zfs-2.2.5. If this is too confusing and you believe something is not right, you can create a pull request here after enabling DEBUG to one and running the debug_releases().

CODE compatibility

#!/bin/bash
DEBUG=0
# Associative array to store compatible releases
declare -A COMPATIBLE_RELEASES
declare -a RANGES
# Function to extract Linux kernel compatibility
parse_linux_compatibility() {
    local url="$1"
    local release_name="$2"
    curl -s $url > $release_name".html"
    # Use grep and sed to extract Linux kernel compatibility line
    local linux_line=$(grep -A10 "Supported Platforms:" "$release_name.html" | grep "Linux kernels" | sed -e 's/^\s*//; s/\s*$//')
    # Check if Linux compatibility line exists
    if [[ -z "$linux_line" ]]; then
        linux_line=$(grep -A10 "Supported Platforms" "$release_name.html" | grep -oP "Linux: compatible with [0-9.]+ - [0-9.]+ kernels" | sed -e 's/^\s*//; s/\s*$//')
    fi
    # Extract the smallest and largest kernel versions using a regex
    if [[ "$linux_line" =~ Linux:\ compatible\ with\ ([0-9.]+)\ -\ ([0-9.]+)\ kernels ]]; then
        min_version="${BASH_REMATCH[1]}"
        max_version="${BASH_REMATCH[2]}"
    fi
    if [[ "$linux_line" =~ Linux\ kernels\ ([0-9]+\.[0-9]+)\ -\ ([0-9]+\.[0-9]+) ]]; then
        min_version="${BASH_REMATCH[1]}"
        max_version="${BASH_REMATCH[2]}"
    fi
    # Store the result in RANGES and COMPATIBLE_RELEASES
    RANGES[0]="$min_version"
    RANGES[1]="$max_version"
    COMPATIBLE_RELEASES["$release_name"]="${RANGES[0]}-${RANGES[1]}"
    return 1
}

populate_releases() {
    # Fetch the releases page content
    curl -s https://github.com/openzfs/zfs/releases > zfs_releases.html
    mapfile -t RELEASES_PAGE < <(
        awk 'BEGIN{RS="<div"; ORS="<div"} /class="Box-body"/{flag=1} flag; /<\/div>/{flag=0}' zfs_releases.html | \
        grep -oP 'href="\/openzfs\/zfs\/releases\/tag\/[^"]+"' | cut -d '"' -f 2
    )
    for url in "${RELEASES_PAGE[@]}"; do
        release_name=$(echo $url | grep -oP 'zfs-.*$')
        # Try to extract Linux kernel compatibility
        parse_linux_compatibility "https://github.com$url" "$release_name"
    done
}
debug_releases() {
    # Print out the compatible releases
    echo "Compatible ZFS Releases:"
    for release in "${!COMPATIBLE_RELEASES[@]}"; do
        echo "$release: Linux kernel ${COMPATIBLE_RELEASES[$release]}"
    done
}
remove_html() {
    rm -f *.html
}
# Check if DEBUG is set to 1
if [[ "$DEBUG" -eq 1 ]]; then
    # Call populate_releases function if DEBUG is enabled
    populate_releases
    debug_releases
fi

update script

This script will update the ZFS module by comparing the one that is installed on the system using compatibility.sh data structures, it will create the needed files in the package.mask folder to avoid pulling in unstable versions of the package; it will compare and install the kernel, compile it, and remove the lowest kernel version. It will also update the bootloader.