CentOS文件备份|还原

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CentOS文件备份|还原

时间:2014-03-18 00:27来源:51cto博客 作者:sailyangfan的空间 举报 点击:205次

dump备份

restore还原

dd数据备份

mkisofs镜像文件制作

 

 

dump备份

dump主要用于备份真个文件系统备份,虽然也可以备份单一目录,但是对目录的支持不足,单一目录还是建议使用打包压缩的方式进行备份

 

dump另一个只要功能就是制定等级,也就是可以进行增量备份。

Center

dump等级分为0~9 10个等级,0是完全备份,1是在0的基础上进行增量备份,依次类推

 

当待备份的数据为单一文件系统

可以利用了level 0~9进行备份,同时可以使用dump完整功能

当待备份的数据只是目录,并非单一文件系统

限制:

所有备份数据必须都在该目录下

仅能使用level 0 进行数据备份

不支持-u参数,即无法创建/etc/dumpdates这个level备份的时间记录文件

 

语法:dump [-Suvj] [-level] [-f备份文件]待备份数据

             dump -W

选项与参数:

-S:仅列出后面的待备份数据需要多少磁盘空间才能够备份完毕

-u:将这次备份记录到/etc/dumpdates文件中

-v:dump文件过程显示出来

-j:加入bzip2的支持,将数据进行压缩,默认压缩等级2

-level:备份等级0~9

-f:备份文件

-W:列出在/etc/fstab里面的具有dump设置的分区是否有过备份

 

 

举例1:备份挂载到/boot文件系统 level -0

[root@localhost ~]# dump -S /boot16752640[root@localhost ~]# dump -u -0 -f /root/boot.dump.0 /boot  DUMP: Date of this level 0 dump: Fri Feb 28 15:05:56 2014  DUMP: Dumping /dev/sda1 (/boot) to /root/boot.dump.0  DUMP: Label: /boot  DUMP: Writing 10 Kilobyte records  DUMP: mapping (Pass I) [regular files]  DUMP: mapping (Pass II) [directories]  DUMP: estimated 16360 blocks.  DUMP: Volume 1 started with block 1 at: Fri Feb 28 15:05:56 2014  DUMP: dumping (Pass III) [directories]  DUMP: dumping (Pass IV) [regular files]  DUMP: Closing /root/boot.dump.0  DUMP: Volume 1 completed at: Fri Feb 28 15:05:58 2014  DUMP: Volume 1 16440 blocks (16.05MB)  DUMP: Volume 1 took 0:00:02  DUMP: Volume 1 transfer rate: 8220 kB/s  DUMP: 16440 blocks (16.05MB) on 1 volume(s)  DUMP: finished in 2 seconds, throughput 8220 kBytes/sec  DUMP: Date of this level 0 dump: Fri Feb 28 15:05:56 2014  DUMP: Date this dump completed:  Fri Feb 28 15:05:58 2014  DUMP: Average transfer rate: 8220 kB/s  DUMP: DUMP IS DONE   [root@localhost ~]# cat /etc/dumpdates /dev/sda1 0 Fri Feb 28 15:05:56 2014 +0800=>可以看出etc/dumpdates记录着这次备份信息

 

举例2:查看文件系统备份记录

[root@localhost ~]# dump -WLast dump(s) done (Dump '>' file systems):> /dev/sda2     (     /) Last dump: never> /dev/sda3     ( /home) Last dump: never  /dev/sda1     ( /boot) Last dump: Level 0, Dat> /dev/sda6     (/mnt/sda6) Last dump: never=>可以看出sda1已经进行了level0备份,其他还未备份

 

举例3:增量备份 level 1

[root@localhost ~]# dd if=/dev/zero of=/boot/bigfile.img bs=1M count=2020+0 records in20+0 records out20971520 bytes (21 MB) copied, 0.320717 seconds, 65.4 MB/s=>先创建一个20M左右的文件[root@localhost ~]# dump -u -1 -f /root/boot.dump.1 /boot  DUMP: Date of this level 1 dump: Fri Feb 28 15:17:51 2014  DUMP: Date of last level 0 dump: Fri Feb 28 15:05:56 2014  DUMP: Dumping /dev/sda1 (/boot) to /root/boot.dump.1  DUMP: Label: /boot  DUMP: Writing 10 Kilobyte records  DUMP: mapping (Pass I) [regular files]  DUMP: mapping (Pass II) [directories]  DUMP: estimated 20543 blocks.  DUMP: Volume 1 started with block 1 at: Fri Feb 28 15:17:52 2014  DUMP: dumping (Pass III) [directories]  DUMP: dumping (Pass IV) [regular files]  DUMP: Closing /root/boot.dump.1  DUMP: Volume 1 completed at: Fri Feb 28 15:17:53 2014  DUMP: Volume 1 20580 blocks (20.10MB)  DUMP: Volume 1 took 0:00:01  DUMP: Volume 1 transfer rate: 20580 kB/s  DUMP: 20580 blocks (20.10MB) on 1 volume(s)  DUMP: finished in 1 seconds, throughput 20580 kBytes/sec  DUMP: Date of this level 1 dump: Fri Feb 28 15:17:51 2014  DUMP: Date this dump completed:  Fri Feb 28 15:17:53 2014  DUMP: Average transfer rate: 20580 kB/s  DUMP: DUMP IS DONE[root@localhost ~]# cat /etc/dumpdates /dev/sda1 0 Fri Feb 28 15:05:56 2014 +0800/dev/sda1 1 Fri Feb 28 15:17:51 2014 +0800=>这次配备写入备份记录中[root@localhost ~]# dump -WLast dump(s) done (Dump '>' file systems):> /dev/sda2     (     /) Last dump: never> /dev/sda3     ( /home) Last dump: never  /dev/sda1     ( /boot) Last dump: Level 1, Date Fri Feb 28 15:17:51 2014> /dev/sda6     (/mnt/sda6) Last dump: never[root@localhost ~]# ll /root/boot* -rw-r--r-- 1 root root 16834560 02-28 15:05 /root/boot.dump.0-rw-r--r-- 1 root root 21073920 02-28 15:17 /root/ boot.dump.1=> boot.dump.1大小约为20M,可见是增量备份

 

举例4:单一目录进行备份

[root@localhost ~]# dump -0 -f /root/etc.dump /etc  DUMP: Date of this level 0 dump: Fri Feb 28 15:23:39 2014  DUMP: Dumping /dev/sda2 (/ (dir etc)) to /root/etc.dumpDUMP: Label: /  DUMP: Writing 10 Kilobyte records  DUMP: mapping (Pass I) [regular files]  DUMP: mapping (Pass II) [directories]  DUMP: estimated 177675 blocks.  DUMP: Volume 1 started with block 1 at: Fri Feb 28 15:23:41 2014  DUMP: dumping (Pass III) [directories]  DUMP: dumping (Pass IV) [regular files]  DUMP: Closing /root/etc.dump  DUMP: Volume 1 completed at: Fri Feb 28 15:24:23 2014  DUMP: Volume 1 188600 blocks (184.18MB)  DUMP: Volume 1 took 0:00:42  DUMP: Volume 1 transfer rate: 4490 kB/s  DUMP: 188600 blocks (184.18MB) on 1 volume(s)  DUMP: finished in 42 seconds, throughput 4490 kBytes/sec  DUMP: Date of this level 0 dump: Fri Feb 28 15:23:39 2014  DUMP: Date this dump completed:  Fri Feb 28 15:24:23 2014  DUMP: Average transfer rate: 4490 kB/s  DUMP: DUMP IS DONE[root@localhost ~]# ll /root/etc.dump -rw-r--r-- 1 root root 193126400 02-28 15:24 /root/etc.dump

 

restore还原

dump备份的文件由restore进行还原

语法:

查看dump文件:restore –t [-f dumpfile] [-h]

比较dump与实际文件:restore –C [-f dumpfile] –D挂载点

进入互动模式(还原单个文件)restore –i [-f dumpfile]

还原整个文件系统:restore –r [-f dumpfile]

 

选项与参数:

相关的各种模式,各种模式无法混用.例如不可以写 -tC

-t:此模式用在察看 dump起来的备份档中含有什么重要数据!类似 tar -t功能;

-C:此模式可以将 dump内的数据拿出来跟实际的文件系统做比较,最终会列出[ dump文件内有记录的,且目前文件系统不一样]的文件;

-i:进入互动模式,可以仅还原部分文件,用在 dump目录时的还原

-r:将整个 filesystem还原的一种模式,用在还原针对文件系统的 dump备份;

 

其他较常用到的选项功能:

-h:察看完整备份数据中的 inode与文件系统 label等信息

-f:后面就接你要处理的那个 dump文件

-D: -C进行搭配,可以查出后面接的挂载点与 dump内有不同的文件

 

 

举例1:查看dump备份文件

[root@localhost ~]# restore -t -f /root/boot.dump.0Dump   date: Fri Feb 28 15:05:56 2014Dumped from: the epochLevel 0 dump of /boot on localhost.localdomain:/dev/sda1Label: /boot         2      .        11      ./lost+found     10041      ./grub     10059      ./grub/grub.conf…….        14      ./System.map-2.6.18-371.el5        15      ./config-2.6.18-371.el5        16      ./symvers-2.6.18-371.el5.gz        17      ./vmlinuz-2.6.18-371.el5

 

举例2:比较文件差异

[root@localhost ~]# mv /boot/message /boot/message-back[root@localhost ~]# restore -C -f /root/boot.dump.0 -D /bootDump   date: Fri Feb 28 15:05:56 2014Dumped from: the epochLevel 0 dump of /boot on localhost.localdomain:/dev/sda1Label: /bootfilesys = /bootrestore: unable to stat ./message: No such file or directorySome files were modified!  1 compare errors

 

举例3:还原整个文件系统

[root@localhost ~]# dd if=/dev/zero of=/home/newfile bs=1M count=200200+0 records in200+0 records out209715200 bytes (210 MB) copied, 3.83857 seconds, 54.6 MB/s[root@localhost ~]# mkfs -t ext3 /home/newfile mke2fs 1.39 (29-May-2006)/home/newfile is not a block special device.……180 days, whichever comes first.  Use tune2fs -c or -i to override.[root@localhost ~]# mount -o loop /home/newfile /mnt[root@localhost ~]# df -h文件系统              容量  已用 可用 已用% 挂载点/dev/sda2             9.5G  4.4G  4.7G  49% //dev/sda3             4.8G  339M  4.2G   8% /home/dev/sda1              99M   42M   53M  45% /boottmpfs                1014M     0 1014M   0% /dev/shm/home/newfile         194M  5.6M  179M   4% /mnt=>创建一个文件挂载到mnt下[root@localhost ~]# cd /mnt[root@localhost mnt]# restore -r -f /root/boot.dump.0restore: ./lost+found: File exists[root@localhost mnt]# ll总计 16149-rw-r--r-- 1 root root    70400 10-01 21:10 config-2.6.18-371.el5drwxr-xr-x 2 root root     1024 02-18 09:51 grub-rw------- 1 root root  2748313 02-18 09:46 initrd-2.6.18-371.el5.imgdrwx------ 2 root root    12288 02-14 18:00 lost+found-rw-r--r-- 1 root root    80032 2009-03-13 message-rw------- 1 root root    27676 02-28 15:54 restoresymtable-rw-r--r-- 1 root root   117436 10-01 21:10 symvers-2.6.18-371.el5.gz-rw-r--r-- 1 root root   996296 10-01 21:10 System.map-2.6.18-371.el5-rw-r--r-- 1 root root 10485760 02-28 13:25 testing.img-rw-r--r-- 1 root root  1912148 10-01 21:10 vmlinuz-2.6.18-371.el5=>还原level 0备份[root@localhost mnt]# restore -r -f /root/boot.dump.1[root@localhost mnt]# ll总计 36711-rw-r--r-- 1 root root 20971520 02-28 15:17 bigfile.img-rw-r--r-- 1 root root    70400 10-01 21:10 config-2.6.18-371.el5drwxr-xr-x 2 root root     1024 02-18 09:51 grub-rw------- 1 root root  2748313 02-18 09:46 initrd-2.6.18-371.el5.imgdrwx------ 2 root root    12288 02-14 18:00 lost+found-rw-r--r-- 1 root root    80032 2009-03-13 message-------- 1 root root    27724 02-28 15:55 restoresymtable-rw-r--r-- 1 root root   117436 10-01 21:10 symvers-2.6.18-371.el5.gz-rw-r--r-- 1 root root   996296 10-01 21:10 System.map-2.6.18-371.el5-rw-r--r-- 1 root root 10485760 02-28 13:25 testing.img-rw-r--r-- 1 root root  1912148 10-01 21:10 vmlinuz-2.6.18-371.el5=>还原level 1备份可以看到多了bigfile.img这个增量文件

 

dd

dd功能不仅限于创建文件,更多功能在于“备份”,cp,dump只是简单的文件数据拷贝,而dd可以读取设备的所有内容,比如superblock ,boot sector,mete data

 

语法:dd if=”input file” of=”output file” bs=”block” count=”number”

选项与参数:

if:输入文件,也可以是设备

of:输出文件,也可以是设备

bs:每个block的大小,默认是512K

count:block数量

 

 

举例1.文件备份

[root@localhost ~]# dd if=~/.bashrc of=/tmp/bashrc 0+1 records in0+1 records out176 bytes (176 B) copied, 7.3142e-05 seconds, 2.4 MB/s[root@localhost ~]# ll /tmp/bashrc -rw-r--r-- 1 root root 176 02-28 16:17 /tmp/bashrc

 

举例2:文件系统备份

[root@localhost ~]# dd if=/dev/sda1 of=/tmp/boot.dd bs=1M 101+1 records in101+1 records out106896384 bytes (107 MB) copied, 9.60492 seconds, 11.1 MB/s[root@localhost ~]# ll /tmp/boot.dd-rw-r--r-- 1 root root 106896384 02-28 16:19 /tmp/boot.dd

 

举例3:文件系统还原

[root@localhost ~]# dd if=/tmp/boot.dd of=/dev/sda1 bs=1M

 

 

举例4.文件系统完全复制

Dump备份时,我们需要先用Dump将文件系统备份,然后创建新的文件系统,格式化,再将备份文件还原到新的文件系统。

使用dd可以不用格式化,就可以完全复制一个文件系统,因为dduperblock ,boot sector,mete data等信息都进行复制,格式化要做的不也正是这些事吗

[root@bogon ~]# fdisk /dev/sda…….Command (m for help): n……Command (m for help): P……   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *           1          13      104391   83  Linux……/dev/sda7            2116        2134      152586   83  LinuxCommand (m for help): w……[root@bogon ~]# partprobe=>创建完分区[root@bogon ~]# dd if=/dev/sda1 of=/dev/sda7 208782+0 records in208782+0 records out106896384 bytes (107 MB) copied, 23.5363 seconds, 4.5 MB/s[root@bogon ~]# mount /dev/sda7 /mnt[root@bogon ~]# ll /mnt总计 5838-rw-r--r-- 1 root root   70400 10-01 21:10 config-2.6.18-371.el5drwxr-xr-x 2 root root    1024 02-18 20:26 grub-rw------- 1 root root 2748762 02-27 19:45 initrd-2.6.18-371.el5.imgdrwx------ 2 root root   12288 02-19 03:59 lost+found-rw-r--r-- 1 root root   80032 2009-03-13 message-rw-r--r-- 1 root root  117436 10-01 21:10 symvers-2.6.18-371.el5.gz-rw-r--r-- 1 root root  996296 10-01 21:10 System.map-2.6.18-371.el5-rw-r--r-- 1 root root 1912148 10-01 21:10 vmlinuz-2.6.18-371.el5=> /mnt和/boot下的内容一样 并且没有进行格式化

 

mkisofs(镜像文件备份)

 

语法:mkisofs [-o镜像文件] [-rv] [-m file]待备份的文件 [-V vol] –graft-point isodir=sysdir

选项与参数:

-o:镜像文件

-r:产生UNIX/Linux支持的文件数据

-v:显示构建ISO的过程

-m:排除的文件

-V:卷标名称

-graft-point:目录对照名称,如果不进行指定所以的信息都会保持在根目录

 

 

举例:

[root@bogon ~]# mkisofs -o /tmp/system.img -r -m /home/lost+found -V 'tkf_file' -graft-point /root=/root /home=/home /etc=/etc[root@bogon ~]# mount -o loop /tmp/system.img /mnt[root@bogon ~]# ll /mntdr-xr-xr-x 114 root root 34816 03-01 14:31 etcdr-xr-xr-x   3 root root  2048 03-01 14:31 homedr-xr-xr-x  18 root root  4096 03-01 14:31 root
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