ㅁ cache drop(초기화)

[root@web01 ~]# cat /proc/sys/vm/drop_caches0[root@web01 ~]# echo 3 > /proc/sys/vm/drop_caches[root@web01 ~]# cat /proc/sys/vm/drop_caches3

ㅁ swapoff -a : 스왑 비활성화(끄기)

[root@web01 ~]# free -mt              total        used        free      shared  buff/cache   availableMem:            987         162         381           7         443         632Swap:          2047           0        2047Total:         3035         162        2429[root@web01 ~]# swapoff -a
[root@web01 ~]# free -mt              total        used        free      shared  buff/cache   availableMem:            987         161         382           7         443         633Swap:             0           0           0Total:          987         161         382
[root@web01 ~]# swapoff -hUsage: swapoff [options] [<spec>]
Options: -a, –all              disable all swaps from /proc/swaps -v, –verbose          verbose mode
 -h, –help     display this help and exit -V, –version  output version information and exit
The <spec> parameter: -L <label>             LABEL of device to be used -U <uuid>              UUID of device to be used LABEL=<label>          LABEL of device to be used UUID=<uuid>            UUID of device to be used <device>               name of device to be used <file>                 name of file to be used
For more details see swapoff(8).

ㅁ swapon -a : 스왑 활성화(켜기)

[[root@web01 ~]# swapon -a[root@web01 ~]# free -mt              total        used        free      shared  buff/cache   availableMem:            987         162         382           7         443         632Swap:          2047           0        2047Total:         3035         162        2430
[root@web01 ~]# swapon -h
Usage: swapon [options] [<spec>]
Options: -a, –all                enable all swaps from /etc/fstab -d, –discard[=<policy>] enable swap discards, if supported by device -e, –ifexists           silently skip devices that do not exist -f, –fixpgsz            reinitialize the swap space if necessary -p, –priority <prio>    specify the priority of the swap device -s, –summary            display summary about used swap devices     –show[=<columns>]   display summary in definable table     –noheadings         don’t print headings, use with –show     –raw                use the raw output format, use with –show     –bytes              display swap size in bytes in –show output -v, –verbose            verbose mode
 -h, –help     display this help and exit -V, –version  output version information and exit
The <spec> parameter: -L <label>             synonym for LABEL=<label> -U <uuid>              synonym for UUID=<uuid> LABEL=<label>          specifies device by swap area label UUID=<uuid>            specifies device by swap area UUID PARTLABEL=<label>      specifies device by partition label PARTUUID=<uuid>        specifies device by partition UUID <device>               name of device to be used <file>                 name of file to be used
Available discard policy types (for –discard): once     : only single-time area discards are issued. (swapon) pages    : discard freed pages before they are reused. * if no policy is selected both discard types are enabled. (default)
Available columns (for –show): NAME  device file or partition path TYPE  type of the device SIZE  size of the swap area USED  bytes in use PRIO  swap priority
For more details see swapon(8).

[출처][hana] cache 초기화 및 swap 초기화 – swappoff swapon|작성자하나자바