Docs Self-Managed Reference rpk Commands rpk redpanda rpk redpanda tune rpk redpanda tune list You are viewing the Self-Managed v24.3 beta documentation. We welcome your feedback at the Redpanda Community Slack #beta-feedback channel. To view the latest available version of the docs, see v24.2. rpk redpanda tune list This command is not supported on macOS, Windows. List available Redpanda tuners and check if they are enabled and supported by your system. To enable a tuner it must be set in the redpanda.yaml configuration file under rpk section, for example: rpk: tune_cpu: true tune_swappiness: true You may use rpk redpanda config set to enable or disable a tuner. Usage rpk redpanda tune list [flags] Flags Value Type Description -r, --dirs strings List of data directories or places to store data (e.g. /var/vectorized/redpanda/); usually your XFS file system on an NVMe SSD device. -d, --disks strings Lists of devices to tune f.e. 'sda1'. -h, --help - Help for list. -m, --mode string Operation Mode: one of: [sq, sq_split, mq]. -n, --nic strings Network Interface Controllers to tune. --reboot-allowed - Allow tuners to tune boot parameters and request system reboot. --config string Redpanda or rpk config file; default search paths are /var/lib/redpanda/.config/rpk/rpk.yaml, $PWD/redpanda.yaml, and /etc/redpanda/redpanda.yaml. -X, --config-opt stringArray Override rpk configuration settings. See rpk -X or execute rpk -X help for inline detail or rpk -X list for terser detail. --profile string Profile to use. See rpk profile for more details. -v, --verbose - Enable verbose logging. Example output The output of the command lists each available tuner and whether it’s enabled or supported (with a reason if it’s unsupported). TUNER ENABLED SUPPORTED UNSUPPORTED-REASON aio_events true true ballast_file true true clocksource true false Clocksource setting not available for this architecture coredump false true cpu true true disk_irq true true disk_nomerges true true disk_scheduler true false open : no such file or directory disk_write_cache true false Disk write cache tuner is only supported in GCP fstrim false false dial unix /var/run/dbus/system_bus_socket: connect: no such file or directory net true true swappiness true true transparent_hugepages false true Tuners This section describes each tuner and their configuration settings in redpanda.yaml. It provides overlapping and additional content to the descriptions returned by rpk redpanda tune help. aio_events The aio_events tuner maximizes throughput by increasing the number of simultaneous I/O requests. It sets the maximum number of outstanding asynchronous I/O operations to be above a calculated threshold. Configuration (yaml): rpk.tune_aio_events: flag to enable the tuner (Default for production mode: true) ballast_file The ballast_file tuner improves debuggability and recoverability of a system with a full disk by creating a ballast file: if the disk becomes full, the ballast file can be deleted, thereby unblocking processes that are failing due to write failures and providing time for operators to stop any problematic processes causing the disk to fill, and to delete topics or records and change retention settings. Configuration (yaml): rpk.tune_ballast_file: flag to enable the tuner (Default for production mode: true) rpk.ballast_file_size: size of the ballast file in bytes (Default for production mode: 1 GiB) rpk.ballast_file_path: path to the ballast file (Default for production mode: /var/lib/redpanda/data/ballast) clocksource The clocksource tuner improves the performance of getting system time by changing the clock source. It sets the clock source to the Time Stamp Counter (TSC) so time can be read in userspace via the Virtual Dynamic Shared Object (vDSO). This is more efficient than the usual virtual machine clock source, xen, that involves the overhead of a system call. Configuration (yaml): rpk.tune_clocksource: flag to enable the tuner (Default for production mode: true) coredump The coredump tuner enables coredumps to be saved for production mode. By default, coredumps are not enabled for production. Enabling this tuner sets the location to save coredumps. Configuration (yaml): rpk.tune_coredump: flag to enable the tuner (Default for production mode: false) rpk.coredump_dir: path to the saved coredump (Default for production mode: /var/lib/redpanda/coredump) cpu The cpu tuner maximizes CPU performance for I/O intensive workloads by optimizing various CPU settings. It performs the following operations: Sets the ACPI-cpufreq governor to performance If system reboot is allowed (rpk redpanda tune --reboot-allowed option is set), the system must be rebooted after the first pass of the tuner, and it performs additional operations: Disables Intel P-states Disables Intel C-states Disables turbo boost After tuning, the system CPUs operate at the maximum non-turbo frequency. Configuration (yaml): rpk.tune_cpu: flag to enable the tuner (Default for production mode: true) disk_irq The disk_irq tuner optimizes the handling of interrupt requests (IRQs) for disks binding all disk IRQs to a requested set of CPUs. It tries to distribute IRQs according to the following guidelines: Distribute NVMe disks IRQs equally among all available CPUs. Distribute non-NVMe disks IRQs equally among designated CPUs or among all available CPUs in the mq mode. IRQs are distributed according to the operation mode set by rpk redpanda tune --mode <operation-mode>. The available operation modes: sq: set all IRQs of a given device to CPU0 sq_split: divide all IRQs of a given device between CPU0 and its HT siblings mq: distribute device IRQs among all available CPUs instead of binding them all to CPU0 If no --mode is specified, a default mode is determined: If there are only NVMe disks, the mq mode is set as the default. For non-NVMe disks: If the number of HT siblings is less than or equal to four, the mq mode is set as the default. Otherwise, if the number of cores is less than or equal to four, the sq mode is set as the default. For all other conditions, the sq_split mode is set as the default. Configuration (yaml): rpk.tune_disk_irq: flag to enable the tuner (Default for production mode: true) rpk redpanda tune --mode <operation-mode> sets the IRQ distribution mode net The net tuner optimizes the handling of interrupt requests (IRQs) for network interfaces (NICs) by binding all NIC IRQs to a requested set of CPUs. Its IRQ distribution operation modes are the same as described for the disk_irq tuner with NICs as the devices. Configuration (yaml): rpk.tune_network: flag to enable the tuner (Default for production mode: true) rpk redpanda tune --mode <operation-mode> sets the IRQ distribution mode disk_nomerges The disk_nomerges tuner reduces CPU overhead by disabling the merging of adjacent I/O requests. Configuration (yaml): rpk.tune_disk_nomerges: flag to enable the tuner (Default for production mode: true) disk_scheduler The disk_scheduler tuner optimizes disk scheduler performance for the type of device (NVME, non-NVME). It provides a selectable set of schedulers: none: minimizes latency of modern NVMe devices by bypassing the operating system’s I/O scheduler noop: preferred for non-NVME devices (and used when none is unavailable), this scheduler uses a simple FIFO queue where all I/O operations are first stored and then handled by the driver. Configuration (yaml): rpk.tune_disk_scheduler: flag to enable the tuner (Default for production mode: true) disk_write_cache The disk_write_cache tuner optimizes performance in Google Cloud Platform (GCP) by enabling write-through caching for its NVMe Local SSD drives. Configuration (yaml): rpk.tune_disk_write_cache: flag to enable the tuner (Default for production mode: true) fstrim The fstrim tuner improves SSD performance by starting a background systemd service to periodically wipe memory blocks that are not used by the file system. This is desirable for SSDs because they require wiping the space where new data will be written, so not wiping during non-write cycles will eventually cause performance degradations, when the lack of free space results in writes triggering synchronous erasures. If it’s available, the fstrim systemd service will be run. If it’s unavailable but systemd is available, an equivalent service will be installed and run. Otherwise, no service will be run. Configuration (yaml): rpk.tune_fstrim: flag to enable the tuner (Default for production mode: true) swappiness The swappiness tuner tunes the kernel to keep process data in-memory for as long as possible instead of swapping it out to disk. Configuration (yaml): rpk.tune_swappiness: flag to enable the tuner (Default for production mode: true) transparent_hugepages Redpanda makes excellent use of operating system-level Transparent HugePages (THP) by pre-allocating memory at startup. For CPUs that support THPs, this results in improved memory page caching and reduced cache misses from translation lookaside buffer (TLB) lookups. Most operating systems configure THP use to madvise by default, meaning a process must explicitly request them. Redpanda is designed to make the required madvise call, meaning THPs are in use under typical operation scenarios. Other possible values for THP use are disabled or always. The transparent_hugepages tuner overrides the operating system setting, configuring THP use to always. This tuner only has a practical effect if the operating system is configured to disabled for THP use. For this reason, this tuner is disabled by default in production mode. It primarily exists to allow operators to ensure THPs are in use for their installations if there is any possibility the operating system is configured to disabled. Configuration (yaml): rpk.tune_transparent_hugepages: flag to enable the tuner (Default for production mode: false) Related topics rpk redpanda tune Back to top × Simple online edits For simple changes, such as fixing a typo, you can edit the content directly on GitHub. Edit on GitHub Or, open an issue to let us know about something that you want us to change. Open an issue Contribution guide For extensive content updates, or if you prefer to work locally, read our contribution guide . 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