Linux File System Management

Linux File System Management
|-File System composition
|-Device Mount
|-Partitioning and formatting principles
|-Disk quotas
|-system Backup

I. Composition of the file system
※/usr/bin,/bin: Holds commands that all users can execute
※/usr/sbin,/sbin: Store only commands that can be executed by root
※/home: User Default host Directory
※/proc: Virtual file system, storing current memory image
※/dev: Storing device files
※/lib: Storage of shared libraries required for System program operation
※/lost+found: To store some system error check results
※/tmp: Storing temporary files
※/ETC: System Configuration file
※/var: Contains frequently changing files, such as mail, log files, scheduled tasks, etc.
※/USR: Store All commands, libraries, manual pages, etc.
※/MNT: Installation point for temporary file system
※/boot: Save location for kernel file and bootstrap program file

Common commands
View Partition usage: df-h|-m
View file, directory size: du
[Email protected] ~]# du-h/etc/services
364k/etc/services
[Email protected] ~]# du-sh/etc
130m/etc
Detect repair File system: fsck, E2fsck (single-user mode execution)
Judging file types: Files
[Email protected] ~]# file/etc/services
/etc/services:ascii 中文版 Text

Using the optical drive
※ Mount Optical Drive
# Mount/dev/cdrom/mnt/cdrom
# Df-h Mount Information
# Cd/mnt/cdrom
# Ls/mnt/cdrom
※ Unmount the optical drive
# Umount/mnt/cdrom
# Eject

Add a disk or partition
Partitioning (FDISK)
Create File System (MKFS)
Try mounting (Mount)
Write configuration file (/etc/fstab)
[Email protected] ~]# DMESG | grep SDB to see if a disk exists
[[email protected] ~]# fdisk-l/DEV/SDA View disk information
1) partition Fdisk/dev/sdb/www 10g/bak
M help
P Show partition Table
n Add a new partition ext3
T change system file type
D Delete Partition
W Save exit
Q Do not save exit
2) Formatting Mkfs
[Email protected] ~]# MKFS.EXT3/DEV/SDB1
3) Mount
[Email protected] ~]# Mkdir/bak
[Email protected] ~]# Mount/dev/sdb1/bak
4) Write the configuration file for automatic mount (/etc/fstab)
label=//ext3 Defaults 1 1
Physical Partition name/Volume label = =/DEV/SDA1
Mount point
File system
Default settings
Whether to detect 1/0
Detection sequence 0,1,2
/dev/sdb1/bak ext3 Defaults 1 2
Add Volume label E2LABEL/DEV/SDB1 backup

Swapfile to dynamically increase swap space
1. # Mkdir/var/swap
# chmod 700/var/swap
2, # dd If=/dev/zero of=/var/swap/file.swp bs=1024k count=64
3. # MKSWAP/VAR/SWAP/FILE.SWP
4, Vi/etc/fstab
/VAR/SWAP/FILE.SWP swap swap defaults 0 0
5. Free
6, Swapon/var/swap/file.swap
7. Free

Second, disk quotas
1. Enable Partition quota function
Edit the/etc/fstab file to add a flag Usrquota or Grpquota on the Mount attribute
/dev/sda3/home ext3 Defaults,usrquota 1 2
Mount-o Remount/home
Temporary settings: Mount-o remount,usrquota/home
2. Set up quota database (enter single user mode)
Quotacheck-cvuga-cvu/test
Generates Aquota.user, aquota.group two files
3. Start Quota function
Quotaon Partition name Quotaon/home quotaoff closing quotas
4. Edit User Quotas
Edquota User name edquota-g user group name
Edquota-t Setting the grace period
Copy user Quotas
Edquota-p template User Replication User 1 replication User 2
Quota command to view user quota usage
Administrator View quota information: repquota-a

Third, system backup
1. Backup
2. Backup partition Ro, umount
3. Compression bzip2
4. Check Md5sum-c
5. Encryption GnuPG Asymmetric Encryption

※CP Command Backup Example
Backup directory:
CP-RPU Backup Directory Destination Directory
-P Keep backup directory and file attributes
-U Incremental Backup
Remote Backup available SCP

※tar Command Use Example
# Tar-zcf/backup/etc_20110303.tar.gz/etc/boot
Backup/etc directory, can package multiple directories at the same time
# TAR-ZCF Bakup_user_20110303.tar.gz/etc/passwd/etc/shadow/etc/group/etc/gshadow
Backup of specified files in/etc directory
# TAR-ZTF Backup_user_20110303.tar.gz
To view a file in a backup package (no package)
# tar-zxf/backup/etc_20110303.tar.gz
Restore/etc directory, default restore to packaged file source directory,-C can specify restore directory
# TAR-ZXF backup_user_20110303.tar.gz Etc/group
Restore only the specified files in the backup

Linux File System Management