View/modify of cache under Linux

Cause:

Memory is not large enough during the installation of OpenStack, and memory is typically set to twice times the amount of memory when it is raised.

The essence of the cache is that the hard disk opens up a space and then sets this space for caching.

View Cache Size

Free-m

Free-m        Total used        free      shared  buff/cache   availablemem:           4799         594        3968           8         235        3981Swap:          3583           0        3583

Find the appropriate hard disk space settings cache: Df-h

Df-hfilesystem               Size  used Avail use% mounted on/dev/mapper/centos-root   50G  2.7G   48G   6%/ Devtmpfs                 2.4G     0  2.4G   0%/devtmpfs                    2.4G  4.0K  2.4G   1%/dev/shmtmpfs                    2.4G  8.4M  2.4G   1%/runtmpfs                    2.4G     0  2.4G   0%/sys/fs/cgroup/dev/loop0               1.9G  6.1M  1.7G   1%/srv/node/swiftloopback/dev/mapper/centos-home   26G   33M   26G   1%/ HOME/DEV/SDA1                497M  210M  288M  43%/boottmpfs                    480M     0  480M   0%/run/user/0

/dev/mapper/centos-root this space in my computer is ample.

Partition cache space: DD command

DD if=/dev/mapper/centos-root of=/home/swap1 bs=1024 count=1048576 4194304+0 Records in4194304+0 Records out4294967296 bytes (4.3 GB) copied, 14.6148 S, 294 mb/sdd If=/dev/zero of=/home/swap bs=1024 count=1048576

　　

Set to Cache

Mkswap/home/swap1

Enable caching

SWAPON/HOME/SWAP1 View the cache information again:

Free-m        Total used        free      shared  buff/cache   availablemem:           4799        2411           8        2207        2111Swap:          7684           1        7683

　　

Boot up

Set to boot

Vi/etc/fstab Add the following command to the last line:/home/swap1 swap default 0 0

View/modify of cache under Linux