Shulou(Shulou.com)06/01 Report--

This article introduces the relevant knowledge of "how to back up data in CentOS". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

Files with backup significance can usually be roughly divided into two categories:

1. Basic system setup information

two。 Content data similar to web services

The files that the operating system itself needs to back up:

1./etc/ entire directory

2./home entire directory

3./var/spool/mail

4./boot

5./root

6. If you have installed other packages, then / usr/local or / opt are also best backed up.

Database aspects of network services

1. The configuration file of the software itself, for example: / etc/ entire directory, / usr/local/ entire directory

two。 Data provided by software services, taking WWW and MySQL as examples

WWW data: / var/www entire directory or / srv/www entire directory, and the user home folder of the system

MySQL:/var/lib/mysql entire directory

3. Other database files that provide services on the Linux host

Recommended directories to be backed up

1./boot

2./etc

3./home

4./root

5./usr/local (or / opt and / srv, etc.)

6./var (Note: if there are some temporary directories in this directory, you don't have to back up)

Directories that do not require backup

1./dev

2./proc

3./mnt and / media

4./tmp

Select backup device

Storage device consideration

Backup speed requirements: think about the use of hard drives

Storage capacity: tape backup consideration

Funding and data reliability: the use of DVD can be preserved for about 10 years

Some common equipment codes:

Optical drive: / dev/cdrom (it should be / dev/sdX or / dev/hdX)

Tape drive: / dev/st0 (SCSI interface), / dev/ht0 (IDE interface)

Floppy disk drive: / dev/fd0,/dev/fd1

Hard disk: / dev/hd [a murd] [1-16] (IDE), / dev/sd [a Meip] [1-16] (SCSI/SATA)

Removable hard drive: / dev/sd [amurp] [1-16] (same as SCSI)

Printer: / dev/lp [0-2]

The type and frequency of backup and the choice of tools

How to back up:

1. Incremental backup

two。 Differential backup

Incremental backup of full backup (Incremental backup)

Consideration of reduction

Principles of incremental backup

The so-called incremental backup refers to the comparison after a period of running after the first full backup of the system.

The difference between the system and the backup files, and then the gold backs up the files that have differences.

Backup software used by incremental backup

The common tools for full backup are: dd, cpio, dupm/restore

Command for direct incremental backup: dupm

Dd if=/dev/sda of=/dev/sdb

Find /-print | cpio-covB > / dev/st0

Cpio-iduv < / dev/st0

1. Full backup

Dump-0u-f / backupdata/home.dump / home

two。 Incremental backup for the first time

Dump-1U-f / backupdata/home.dump.1 / home

Tar-exclude / proc-exclude / mnt-exclude / tmp\

-- exclude / backupdata-jcvp-f / backupdata/sys.tar.bz2

Differential backup of full backup (differential backup)

The difference in backup value is that each backup is compared with the original full backup.

Tar-N '2009-06-01'-jpcv-f / backupdata/home.tar.bz2 / home

Rsync-av source directory destination directory

Rsync-av / home/ backupdata/ (mirror / home/ to / backupdata/home/)

Rsync-av / home / backupdata/ (it will be much faster to do it again, and almost nothing will be done if the data remains unchanged)

Critical data backup

Tar-jpcvf mysql.`date +% Ymuri% mmury% d`.tar.bz3 / var/lib.mysql

This is the end of "how CentOS backs up data". Thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

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