File systems for Linux

Computer Open Order

Underlying hardware startup, self-test-system boot load-kernel load-root directory--/sbin/init

File System Management:

1, mount, the file system with the existing root directory to establish a connection, so that the file system as the Access interface

2, uninstall, release this connection relationship

Note: The device being used in the process cannot be uninstalled

Mount method: 1, Mount [options] ... [-O] device/dir mount new device

2. Mount device to view all mounted devices

Device: Indicates which devices to mount

1. Device Name

2, Volume label-l ' label '

3. UUID:-uuid

Dir: Indicates the mount point. It is best to have no other file under the mount point, otherwise the file will be blocked

Option:-T: type of file device to mount

-R: Read-only Mount

-W: Read-write Mount

-A: Automatically mount all devices that support automatic mounting

-N: Do not update/etc/mtab

-o: Option to mount file system

Async/sync: Asynchronous mode \ Synchronous mode

Atime/time: Access timestamp for directories and files

Auto/noauto: Whether auto mount is supported

Exec/noexec: Whether to support the loading of applications on file systems as processes

Dev/nodev: Whether to support the use of device files on this file system

RO: Read-only, RW: Read/write

User/nouser: Whether to support normal user mount this device

Default mount options:

1, defaults:

Async,rw,dev,exec,auto,nouser

Uninstall command: Umount/mount_print

Umount DEVICE

To view the processes that are accessing this file system:

Fuser-v/mount_print

-KM: Aborts all directories that are accessing the specified file system

Mount Swap partition: Swapon, enable

swapon [option] ... device

-A: Activate all swap partitions

-P: Specify priority

Swapoff: Disable

Memory Space usage query: free [option] ...

-M: In M-G: in units

Viewing tools for information such as file system space occupancy

Df:-h in the way people think to understand

-I: The inode is displayed and does not show block.

View the overall space consumption status of a directory

Du-h: The way people think and understand

-S: Overall directory size

Mount mounted file system does not load automatically at startup

File system mounted configuration file:

/etc/fstab

The last item is: Self-Test order, 0 not self-Test 1: First self-test, generally only rootfs used

Other concepts of the file system

Address pointers: direct pointers, indirect pointers, level three pointers

Link file

1. Hard links point to different paths of the same inode. Create a hard link to create a different link for the Inode

Hard links cannot be made to the directory (System comes with the ability to create hard links)

Hard links cannot be made across partitions

2. The symbolic link can be used in the directory

Can span partitions

The path to the other file has a size that points to the length of the path

Create a linked file: ln [-SV] src DEST

-S: Create a soft connection without s is to create a hard link

User interaction for Bash programming; read [option] ... [Name] ...

-P: Information displayed

-T: Displayed time

Bash-n/path/to/... Verify that the script has syntax errors

File systems for Linux