Disk and File System Management (III)

A. Swap partition

1.free command--View the current system's swap partition and physical memory usage

-M: Displayed in m (default in bytes)

Fdisk command, adjust the partition type to 82

To create a swap partition:

Mkswap/dev/sda2

-L LABEL

SWAPON/DEV/SDA2 switching on swap partition

-A: Enable all switching devices defined in the/etc/fstab file

SWAPOFF/DEV/SDA2 switching off swap partition

2. Loopback devices

Loopback, using software to simulate the implementation of hardware

DD command: Convert and copy a file the same as copy, DD can copy only part of the file data, copy the bits and copy of the duplicate is not the same

if= Data sources

of= Data storage target

Bs=1

count=2

seek=#: The size of skipped space when creating a data file

Usage: DD if= data source file of= Target storage directory bs= file size per copy count= copy several times

DD IF=/DEV/SDA of=/mnt/usb/mbr.backup bs=512 count=1 copy MBR table

Three./etc/fstab file system automatically mount file system after boot

1. There are 6 fields in the file

A. Devices to be mounted

B. Mount point

C. File system type

D. Mount Options

E. Dump frequency (make a full backup every few days)

F. File system detection order (only the root can be 1)

/dev/sda5/mnt/testext3defaults 0 0

Mount-a: Mount all file systems defined in the/etc/fstab file

2.fuser: Verifying that a file or socket file is in use by the process

-V: View running processes on a file

-K: Kill Process

-M: Specify mount point

FUSER-KM Mount_point: Terminates all processes that are accessing this mount point

This article is from "Luo Chen's blog" blog, please be sure to keep this source http://luochen2015.blog.51cto.com/9772274/1641889

Disk and File System Management (III)