跟老韩学UbuntuServer2204vmstat指令帮助手册

　　vmstat指令帮助手册
　　vmstat可查看ubunt linux的综合性能，是每个从事Linux人员必知必会、需掌握的核心指令之一。
　　vmstat指令帮助手册如下。VMSTAT(8)                                        System Administration                                       VMSTAT(8)  NAME        vmstat - Report virtual memory statistics  SYNOPSIS        vmstat [options] [delay [count]]  DESCRIPTION        vmstat reports information about processes, memory, paging, block IO, traps, disks and cpu activity.         The  first report produced gives averages since the last reboot.  Additional reports give information on a sam‐        pling period of length delay.  The process and memory reports are instantaneous in either case.  OPTIONS        delay  The delay between updates in seconds.  If no delay is specified, only one report is printed with the av‐               erage values since boot.         count  Number of updates.  In absence of count, when delay is defined, default is infinite.         -a, --active               Display active and  inactive memory, given a 2.5.41 kernel or better.         -f, --forks               The  -f switch displays the number of forks since boot.  This includes the fork, vfork, and clone system               calls, and is equivalent to the total number of tasks created.  Each process is represented  by  one  or               more tasks, depending on thread usage.  This display does not repeat.         -m, --slabs               Displays slabinfo.         -n, --one-header               Display the header only once rather than periodically.         -s, --stats               Displays a table of various event counters and memory statistics.  This display does not repeat.         -d, --disk               Report disk statistics (2.5.70 or above required).         -D, --disk-sum               Report some summary statistics about disk activity.         -p, --partition device               Detailed statistics about partition (2.5.70 or above required).         -S, --unit character               Switches  outputs  between  1000  (k),  1024 (K), 1000000 (m), or 1048576 (M) bytes.  Note this does not               change the block (bi/bo) fields, which are always measured in blocks.         -t, --timestamp               Append timestamp to each line         -w, --wide               Wide output mode (useful for systems with higher amount of memory, where the default output mode suffers               from unwanted column breakage).  The output is wider than 80 characters per line.         -V, --version               Display version information and exit.         -h, --help               Display help and exit.  FIELD DESCRIPTION FOR VM MODE    Procs        r: The number of runnable processes (running or waiting for run time).        b: The number of processes blocked waiting for I/O to complete.     Memory        These are affected by the --unit option.        swpd: the amount of swap memory used.        free: the amount of idle memory.        buff: the amount of memory used as buffers.        cache: the amount of memory used as cache.        inact: the amount of inactive memory.  (-a option)        active: the amount of active memory.  (-a option)     Swap        These are affected by the --unit option.        si: Amount of memory swapped in from disk (/s).        so: Amount of memory swapped to disk (/s).     IO        bi: Blocks received from a block device (blocks/s).        bo: Blocks sent to a block device (blocks/s).     System        in: The number of interrupts per second, including the clock.        cs: The number of context switches per second.     CPU        These are percentages of total CPU time.        us: Time spent running non-kernel code.  (user time, including nice time)        sy: Time spent running kernel code.  (system time)        id: Time spent idle.  Prior to Linux 2.5.41, this includes IO-wait time.        wa: Time spent waiting for IO.  Prior to Linux 2.5.41, included in idle.        st: Time stolen from a virtual machine.  Prior to Linux 2.6.11, unknown.  FIELD DESCRIPTION FOR DISK MODE    Reads        total: Total reads completed successfully        merged: grouped reads (resulting in one I/O)        sectors: Sectors read successfully        ms: milliseconds spent reading     Writes        total: Total writes completed successfully        merged: grouped writes (resulting in one I/O)        sectors: Sectors written successfully        ms: milliseconds spent writing     IO        cur: I/O in progress        s: seconds spent for I/O  FIELD DESCRIPTION FOR DISK PARTITION MODE        reads: Total number of reads issued to this partition        read sectors: Total read sectors for partition        writes : Total number of writes issued to this partition        requested writes: Total number of write requests made for partition  FIELD DESCRIPTION FOR SLAB MODE        cache: Cache name        num: Number of currently active objects        total: Total number of available objects        size: Size of each object        pages: Number of pages with at least one active object  NOTES        vmstat does not require special permissions.         These  reports  are intended to help identify system bottlenecks.  Linux vmstat does not count itself as a run‐        ning process.         All linux blocks are currently 1024 bytes.  Old kernels may report blocks as 512 bytes,  2048  bytes,  or  4096        bytes.         Since procps 3.1.9, vmstat lets you choose units (k, K, m, M).  Default is K (1024 bytes) in the default mode.         vmstat uses slabinfo 1.1  FILES        /proc/meminfo        /proc/stat        /proc/*/stat  SEE ALSO        free(1), iostat(1), mpstat(1), ps(1), sar(1), top(1)  BUGS        Does not tabulate the block io per device or count the number of system calls.  AUTHORS        Written by Henry Ware ⟨al172@yfn.ysu.edu⟩.        Fabian Frédérick ⟨ffrederick@users.sourceforge.net⟩ (diskstat, slab, partitions...)  REPORTING BUGS        Please send bug reports to ⟨procps@freelists.org⟩  procps-ng                                             2020-06-04                                             VMSTAT(8)