Linux Disk Management and file system management

First, the basic knowledge of the disk

1. Disk classification

Mechanical hard-disk

Solid-state Drives

2. Disk interface type:

IDE: Under Linux file name/dev/hd[a-d], maximum speed up to 133MBytes

SCSI: Under Linux file name/dev/sd[a-z], up to a maximum rate of 640MBytes

SATA: Under Linux file name/dev/sd[a-z], up to a maximum rate of 6Gbps

SAS: Under Linux file name/dev/sd[a-z], maximum speed up to 6Gbps

USB: Under Linux file name/dev/sd[a-z], maximum speed up to 480MBytes

3, the partition of the disk:

Primary partition (primary) and extended partition (exended):/dev/sd[1-4],

Logical Partitioning (logicalpartition): Starting from/dev/sd5,

4. Device Number:

Major: Differentiating device types

Minor: distinguish between different devices of the same device type

Second, disk partitioning tool

1. Fdisk: Support for up to 15 partitions on a single hard drive

Options:

-L: List all disk devices

Sub-command:

P: Show Partition list

N: Create a new partition

D: Delete partition

T: Modify the partition ID

L: List all support ID types

W: Save exit

Q: Exit does not save

M: Get Help

See if the kernel and the new partition are recognized: cat/proc/partitions

Let the kernel reread the disk partition table:

CentOS 5:partprobe [DEVICE]

CentOS 6 and 7:partx–a [DEVICE]

KPARTX–AF [DEVICE]

Third, file System management

1, File system classification:

Linux:ext2,ext3,ext4,reiserfs,xfs,btrfs,swap

Ext2 is not a log file, ext3 is a log file

Disc: ISO9660

Windows:fat32,ntfs

Unix:ffs,ufs,jfs,jfs2

Network File system: Nfs,cifs

Cluster file system: OCFS2,GFS2

Distributed File System: Ceph

2. Create File system

MKFS command: MKFS [-v] [-t fstype] [fs-options] filesys [blocks]

Options:

-T: Specifies the system file type, equivalent to Type=mkfs.type

MKE2FS (ext type only): Mke2fs [OPTION] ... DEVICE

Options:

-T: Specify the System file type

-B: Specify the size of each block (supports 1024,2048,4096)

-I: Specify the number of bytes per Inode

-C: Check for disk errors

-L: Specify the volume label name

-j: equivalent to mke2fs–t ext3

-N: Specifies how many inode the file system has

-M: Specify a percentage of the reserved space

3. File Decency Properties View and adjustment tool:

E2label:e2label device [New-label]

View Volume Label: E2label/dev/device

Set Volume Label: E2label/dev/device "LABEL"

TUNE2FS: Displays the properties of the Ext series file system and adjusts its properties

Options:

-L: Displays information in the Super block

-L: Modify the volume label

-j: equivalent to mke2fs–t ext3

-M: Specify a percentage of the reserved space

-O: File System properties are enabled or closed

-O: File system default mount option enabled or closed

DUMPE2FS:

Dumpe2fs–h/dev/device: Show only Super block information

Super BLOCK: is a place to record information about the entire file system, the main information is:

1. Total Block and Inode

2. Unused and used Inode and block number

3. Size of block and inode

4, the file system mount time, the last time the data was written, the last time to verify the disk

5, valid bit value, mounted as 0, not mounted as 1

4, the File system detection

Fsck:

Options:

-T: Specify the System file type

-A: Automatic detection of problematic fans

-R: Interactive check

-F: Forced check

-D: Optimized configuration for directories under the file system

E2fsck:ext Series file system-specific detection and repair tools

5. File system mount and use

mount:mount [Options] [-o options] DEVICE mount_point

[Options]: Options command

-T: Specifies the type of file to mount

-A: Mount all non-mounted disks according to/ETC/FSTAB data

-L: Specify the volume label name

-r: Mount this file system as "read-only" mode

-W: Mount this file system in read-write mode

-B: Bind directory to another directory

-N: Each file system automatically updates the/etc/mtab file when it is mounted, and-n is used to disallow this function; At this point, if you want to view all file systems mounted Cat/proc/mounts

[-O options]: Mount options

Async: Async Mode

Sync: Synchronous mode

Remount: Re-mount

ACL: whether to support the use of FACL on this device

User/nouser: Whether to allow normal mount of this device

Atime/noatime: Whether more access timestamp

Auto/noauto: Whether this device is allowed to be mounted automatically

Diratime/nodiratime: Whether to update the access timestamp of the directory

Exec/noexec: Whether the application on this file system is allowed to execute

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

Defaults: including Rw,suid,dev,exec,auto,nouser,async

Device: Devices to be mounted (can be device files, volume labels, UUID, pseudo file system names)

Mount_point: Mount point

Umount: Uninstalling

Umount DEVICE

Umonut Mount_point

To view the process that is accessing the specified mount point: Fuser–v mount_point

Terminates all processes that are accessing the specified mount point: fuser:-km mount_point

Iv. Swap partitions:

Free: view memory and swap usage status

-M: in megabytes

-G: in gigabytes

Mkswap: Creating Swap partitions

mkswap [option] DEVICE

Swapon: Enable swap partition

swapon [option] [DEVICE]

-A: Activate all swap partitions

-P: Set priority

Swapoff: Disable swap partition

swapoff [option] [DEVICE]

File system space occupancy Information viewing tool

df: View partition status

DF [OPTION] ... [FILE] ...

Options:

-A: Displays all file systems, including/proc and other file systems

-K: Display file system in Kbytes

-M: Display file system in MBytes

-H: Displayed in human readable form

-I: Displayed as the number of inode

-P: Output in POSIX-compatible format

Du

Du [OPTION] ... [FILE] ...

-K: Display file system in Kbytes

-M: Display file system in MBytes

-H: Displayed in human readable form

-A: Displays the capacity of all files and directories

5. File system mounted configuration file:/etc/fstab

Use the content shown in Cat/etc/fstab to define a file system for each row, with the contents of each line:

Device or pseudo-file to mount:

Device file, LABEL, UUID, pseudo file system name

Mount point

File system type

Mount option: Default

Dump frequency: 0 for no dump, 1 for daily dump, 2 for every other day dump

Self-Test sequence: 0 is not self-test, 1 is the first self-test, usually only/only 1

6. link file on file system

Hard links: Two paths to the same inode (not for directories and cross-partitions)

Symbolic Link: The data of a linked file points to another file path

LN:LN [-S] SRC DEST

This article is from the "Summer Month" blog, please make sure to keep this source http://lkc0110.blog.51cto.com/3410558/1694123

Linux Disk Management and file system management