(Linux学习笔记一:压缩)[20180209]

学习笔记一：压缩

2015年2月5日

上午 10:23

压缩命令

压缩文件的扩展名大多是*.tar、*.tar.gz、*.tgz、*.gz、*.Z、*.bz2

常见的压缩命令gzip与bzip2，其中bzip2压缩比gzip要好

tar可以用来进行文件打包，并可支持gzip和bzip2的压缩

压缩 tar -jvc -f  filename.tar.bz2 /directory

查询 tar -jtv -f  filename.tar.bz2

解压 tar -jxv -f filename.tar.bz2 -C /puorose/directory

Dump 命令可备份文件系统或单一目录

Dump 的备份若针对文件系统时，可进行0~9的level差异备份。其中level为0为完整备份

restore命令可以还原被dump构建的备份文件

要新建光盘刻录数据时，可通过mkisofs命令来构建

可通过cdrecord来写入CD或DVD刻录机

dd可备份完整的分区或磁盘，因为dd可读取硬盘的扇区表面数据

cpio为相当优秀的备份命令，不过必须要搭配类似find命令来读入预备份文件

测试演练

gzip与bzip2压缩

 

tar打包

使用gzip压缩格式并且排除log和bz压缩档

[oracle@xitest01 schema]$  tar -zcv -f schema_tar_test.tar.gz --exclude=/u03/schema/*.log --exclude=/u03/schema/*.bz   /u03/schema

使用bzip2压缩格式并且排除log和gz压缩档

[oracle@xitest01 schema]$  tar -jcv -f schema_tar_test.tar.bz2 --exclude=/u03/schema/*.log --exclude=/u03/schema/*.gz   /u03/schema

查看两者压缩比例

[oracle@xitest01 schema]$ du -sh schema_tar_test.tar.*

160K    schema_tar_test.tar.bz2

260K    schema_tar_test.tar.gz

dump备份文件系统

模拟一个文件盘符

[root@xitest01 u04]# dd if=/dev/zero of=/u04/loop_mount bs=1M count=1024

1024+0 records in

1024+0 records out

1073741824 bytes (1.1 GB) copied, 8.35942 seconds, 128 MB/s

[root@xitest01 u04]#  mkfs.ext3 /u04/loop_mount

[root@xitest01 u04]# mount -o loop  /u04/loop_mount /u04/mount_loop

[root@xitest01 u04]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/sda2             9.7G  5.4G  3.9G  59% /

/dev/sda6              31G  1.9G   28G   7% /u02

/dev/sda5              30G   21G  7.1G  75% /u01

/dev/sda1             190M   23M  158M  13% /boot

tmpfs                1005M     0 1005M   0% /dev/shm

/dev/sdb              504G  263G  216G  55% /u03

/dev/sdc1             504G  312G  167G  66% /u04

/u04/loop_mount      1008M   34M  924M   4% /u04/mount_loop

创建dump备份目录

[root@xitest01 u04]# mkdir backup

[root@xitest01 u04]#  dump -0 -j -f /u04/backup/dump.bak /u04/loop_mount

 DUMP: Dumping /dev/sdc1 (/u04 (dir /loop_mount)) to /u04/backup/dump.bak

  DUMP: Label: none

  DUMP: Writing 10 Kilobyte records

  DUMP: Compressing output at compression level 2 (bzlib)

  DUMP: mapping (Pass I) [regular files]

  DUMP: mapping (Pass II) [directories]

  DUMP: estimated 1067027 blocks.

  DUMP: Volume 1 started with block 1 at: Thu Feb  5 10:08:25 2015

  DUMP: dumping (Pass III) [directories]

  DUMP: dumping (Pass IV) [regular files]

  DUMP: Closing /u04/backup/dump.bak

  DUMP: Volume 1 completed at: Thu Feb  5 10:09:01 2015

  DUMP: Volume 1 took 0:00:36

  DUMP: Volume 1 transfer rate: 156 kB/s

  DUMP: Volume 1 1067020kB uncompressed, 5627kB compressed, 189.626:1

  DUMP: 1067020 blocks (1042.01MB) on 1 volume(s)

  DUMP: finished in 36 seconds, throughput 29639 kBytes/sec

  DUMP: Date of this level 0 dump: Thu Feb  5 10:08:25 2015

  DUMP: Date this dump completed:  Thu Feb  5 10:09:01 2015

  DUMP: Average transfer rate: 156 kB/s

  DUMP: Wrote 1067020kB uncompressed, 5627kB compressed, 189.626:1

  DUMP: DUMP IS DONE

[root@xitest01 u04]# ls -l /u04/backup/

total 5640

-rw-r--r-- 1 root root 5762814 Feb  5 10:09 dump.bak

[root@xitest01 u04]# du -sh /u04/backup/

5.6M    /u04/backup/

测试加入文件至目录

[root@xitest01 u04]# cp ogg.tar.gz /u04/mount_loop/

[root@xitest01 u04]# du -sh /u04/mount_loop/

503M    /u04/mount_loop/

[root@xitest01 u04]# dump -1 -j -f /u04/backup/dump.bak /u04/loop_mount

DUMP: Only level 0 dumps are allowed on a subdirectory (不是单一文件系统)

  DUMP: The ENTIRE dump is aborted.

备份boot盘符测试

[root@xitest01 u04]# dump -0 -j -f /u04/backup/dump_boot.bak  /dev/sda1

[root@xitest01 u04]# dump -1 -j -f /u04/backup/dump_boo01.bak /dev/sda1

 DUMP: WARNING: There is no inferior level dump on this filesystem

  DUMP: WARNING: Assuming a level 0 dump by default (boot目录也没差异备份吗？)

[root@xitest01 u04]# cd /u04/backup/

[root@xitest01 backup]# ls

dump.bak  dump_boo01.bak  dump_boot.bak

[root@xitest01 backup]# du -sh *

5.6M    dump.bak

16M     dump_boo01.bak

16M     dump_boot.bak

 

 

 

Database	Ip	Gzip		Bzip2
xxxxx	xxx.xxx.xxx.xxx	2015/3/22 10:22:00 ~2015/3/23 01:5600 3小時	16GB	2015/03/25 09:05~2015/03/26 00:56 16小時	9.2GB