Commonly used · Observation system

free:View memory overview

Syntax

free [-h | -m]

Options

-h / -m

Teaching Compatibility Options

Examples

free -m

Usage and sandbox support

Fixed teaching memory value; no real-time sampling.

Hands-on exercises

• View memory overviewEveryday

Full documentation ↗

Related commands

• psView process list
• pgrepCheck process number by name
• killSend signal to process
• pkillEnd process by name
• topView system process snapshot
• dfView file system space
• duEstimated directory usage
• unameView kernel information
• whoamiShow current user
• idView users and user groups
• hostnameView host name
• dateView date
• uptimeView running time
• nprocQuery the number of available processors
• whoView login session
• wView sessions and load
• ttyView terminal device name
• lscpuView CPU topology
• lsblkView block devices and file systems
• findmntView mounting relationships
• vmstatObserve memory and CPU indicators
• dmesgView kernel messages
• htopInteractively view process resources
• lsofView open files and ports
• fuserFind processes occupying files or ports
• iostatWatch the disk with the CPU indicator
• pidstatObserve process resource usage
• sarQuery system performance records
• niceSpecify process scheduling priority
• reniceAdjust the priority of existing processes
• ioniceAdjust I/O scheduling priority
• straceTracing system calls
• perfSampling performance events
• mountMount file system
• umountUnmount file system
• blkidQuery block device identifier
• fdiskView or edit partitions
• partedManage disk partitions
• mkfsCreate file system
• fsckCheck file system
• swaponEnable or query swap space
• swapoffDisable swap space
• lsmodList kernel modules
• modinfoQuery kernel module information
• modprobeLoad kernel module
• lsusbView USB device
• lspciView PCI device
• getconfView system configuration values