服务器评测首先弄清楚何为全备、增量备份、差异备份。简而言之，可以这样理解：
- 全备：对所有的文件做一次备份。
- 增量备份：本次和上一次的的差异。
- 差异备份：在全备的基础上做备份。
相关阅读： dump和restore命令实现全备、增量备份和差异备份 http://www.linuxidc.com/Linux/2013-08/89041.htm
一 tar命令
#创建测试文件夹和文件
[root@serv01 web]# cd /data
[root@serv01 data]# ls
[root@serv01 data]# mkdir /work
[root@serv01 data]# mkdir /work/upload
[root@serv01 data]# cd /work/upload/
[root@serv01 upload]# touchaa0{1,2,3,4,5}.txt
[root@serv01 upload]# ls
aa01.txt aa02.txt aa03.txt aa04.txt aa05.txt
#创建压缩包
[root@serv01 data]# tar -cvf upload01.tar/work/upload/
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
#查看压缩包里面包含的文件
[root@serv01 data]# tar -tf upload01.tar
work/upload/
work/upload/aa03.txt
work/upload/aa01.txt
work/upload/aa04.txt
work/upload/aa05.txt
work/upload/aa02.txt
#删除掉数据，模拟数据丢失
[root@serv01 data]# rm -rf /work
#解压
[root@serv01 data]# tar -xvf upload01.tar-C /
work/upload/
work/upload/aa03.txt
work/upload/aa01.txt
work/upload/aa04.txt
work/upload/aa05.txt
work/upload/aa02.txt
[root@serv01 data]# ls /work
upload
[root@serv01 data]# ls
upload01.tar
#压缩时包含文件路径
[root@serv01 data]# tar -cPvf upload02.tar/work/upload/
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
#解压时就不需要指定文件路径了
[root@serv01 data]# tar -xPvf upload02.tar
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
[root@serv01 data]# ls /work/
upload
#不一定需要f参数，可以使用重定向解决
[root@serv01 data]# tar -cv upload03.tar/work/upload/
tar: upload03.tar: Cannot stat: No suchfile or directory
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
work/upload/00007550000000000000000000000000121766767060120445ustar rootrootwork/upload/aa03.txt00006440000000000000000000000000121766767060133170ustar rootrootwork/upload/aa01.txt00006440000000000000000000000000121766767060133150ustar rootrootwork/upload/aa04.txt00006440000000000000000000000000121766767060133200ustar rootrootwork/upload/aa05.txt00006440000000000000000000000000121766767060133210ustar rootrootwork/upload/aa02.txt00006440000000000000000000000000121766767060133160ustar rootroottar: Exiting with failurestatus due to previous errors
#指定路径，重定向到upload03.tar
[root@serv01 data]# tar -cv /work/upload/> upload03.tar
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
#删除目录
[root@serv01 data]# rm -rf /work/
#解压，指定输入源
[root@serv01 data]# tar -xv -C / <upload03.tar
work/upload/
work/upload/aa03.txt
work/upload/aa01.txt
work/upload/aa04.txt
work/upload/aa05.txt
work/upload/aa02.txt
#查看
[root@serv01 data]# ls /work/
upload
[root@serv01 data]# tar -tf upload03.tar
work/upload/
work/upload/aa03.txt
work/upload/aa01.txt
work/upload/aa04.txt
work/upload/aa05.txt
work/upload/aa02.txt
#测试路径加的不一样的效果
[root@serv01 data]# cd /work/
[root@serv01 work]# tar -cf upload04.tarupload/
[root@serv01 work]# tar -tf upload04.tar
upload/
upload/aa03.txt
upload/aa01.txt
upload/aa04.txt
upload/aa05.txt
upload/aa02.txt
#会解压到根下面的upload目录下
[root@serv01 work]# tar -xv -C / <upload04.tar
upload/
upload/aa03.txt
upload/aa01.txt
upload/aa04.txt
upload/aa05.txt
upload/aa02.txt
[root@serv01 work]# ls /upload/
aa01.txt aa02.txt aa03.txt aa04.txt aa05.txt
#创建aa06.txt文件
[root@serv01 upload]# touch aa06.txt
[root@serv01 upload]# cd /data
[root@serv01 data]# tar -tf upload02.tar
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
#增加aa06.txt到upload02.tar中
[root@serv01 data]# tar -Pvf upload02.tar-r /work/upload/aa06.txt
/work/upload/aa06.txt
[root@serv01 data]# tar -tf upload02.tar
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
/work/upload/aa06.txt
#演示文件修改后，更新压缩包
#编辑文件
[root@serv01 data]# vim/work/upload/aa01.txt
#更新
[root@serv01 data]# tar -uPvf upload02.tar/work/upload/
/work/upload/aa01.txt
[root@serv01 data]# tar -tf upload02.tar
tar: Removing leading `/’ from member names
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
/work/upload/aa06.txt
/work/upload/aa01.txt
#删除文件，然后恢复
[root@serv01 data]# rm -rf /work/
[root@serv01 data]# ls /work/*
ls: cannot access /work/*: No such file or directory
[root@serv01 data]# tar -xPvf upload02.tar
/work/upload/
/work/upload/aa03.txt
/work/upload/aa01.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa02.txt
/work/upload/aa06.txt
/work/upload/aa01.txt
#查看刚才更新的文件，发现没任何问题
[root@serv01 data]# cat/work/upload/aa01.txt
this is aa01.txt
#找到etc下面以conf结尾的文件，然后打包
[root@serv01 data]# find /etc/ -name”*.conf” | xargs tar -Pcvf test01.tar
#找到etc下面以conf结尾的文件，但不包含yum.conf，然后打包
[root@serv01 data]# find /etc/ -name”*.conf” ! -name “yum.conf” | xargs tar -Pcvf test02.tar
[root@serv01 data]# find /etc/ -name”*.conf” ! -name yum.conf | xargs tar -Pcvf test02.tar
#指定文件，然后备份
#将配置文件写到file1
[root@serv01 data]# find /etc -name”*.conf” > file1
#查看文件，可以看到所有的配置文件列表都已经存在了（注意是文件路径）
[root@serv01 data]# vim file1
#创建conf01.tar，然后T指定文件
[root@serv01 data]# tar -cPvf conf01.tar -Tfile1
[root@serv01 data]# tar -tf conf01.tar
[root@serv01 data]# ls -h conf01.tar -l
-rw-r–r—. 1 root root 250K Aug 2 18:18 conf01.tar
接下来请看第2页精彩内容： http://www.linuxidc.com/Linux/2013-08/89042p2.htm
二 tar命令实现——全备和增量备份
[root@serv01 data]# ls /work/upload/
aa01.txt aa02.txt aa03.txt aa04.txt aa05.txt aa06.txt
[root@serv01 data]# rm -rf upload01.tar
#这是全备，无法实现增量备份功能
[root@serv01 data]# tar -cPvf upload01.tar/work/upload/
#g指定标志文件
[root@serv01 data]# tar -g flag -cPvfupload01.tar /work/upload/
tar: /work/upload: Directory is new
/work/upload/
/work/upload/aa01.txt
/work/upload/aa02.txt
/work/upload/aa03.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa06.txt
[root@serv01 data]# vim flag
#新建文件
[root@serv01 data]# touch /work/upload/aa07.txt
#更改文件
[root@serv01 data]# vim/work/upload/aa02.txt
[root@serv01 data]# tar -g flag -cPvfupload02.tar /work/upload/
/work/upload/
/work/upload/aa02.txt
/work/upload/aa07.txt
[root@serv01 data]# tar -tPf upload02.tar
/work/upload/
/work/upload/aa02.txt
/work/upload/aa07.txt
[root@serv01 data]# touch/work/upload/aa08.txt
[root@serv01 data]# rm -rf/work/upload/aa01.txt
[root@serv01 data]# ls /work/upload/
aa02.txt aa03.txt aa04.txt aa05.txt aa06.txt aa07.txt aa08.txt
[root@serv01 data]# tar -g flag -cPvfupload03.tar /work/upload/
/work/upload/
/work/upload/aa08.txt
#恢复全备，逐次恢复
#数据丢失
[root@serv01 data]# rm -rf /work/*
[root@serv01 data]# ls /work/
#先恢复全备
[root@serv01 data]# tar -g flag -xPvfupload01.tar
/work/upload/
/work/upload/aa01.txt
/work/upload/aa02.txt
/work/upload/aa03.txt
/work/upload/aa04.txt
/work/upload/aa05.txt
/work/upload/aa06.txt
#可以看到数据回来了
[root@serv01 data]# ls /work/upload/
aa01.txt aa02.txt aa03.txt aa04.txt aa05.txt aa06.txt
#查看aa02.txt文件，发现内容没有
[root@serv01 data]# cat/work/upload/aa02.txt
#恢复文件，从增量备份upload02.tar文件中来
[root@serv01 data]# tar -g flag -xPvfupload02.tar
/work/upload/
/work/upload/aa02.txt
/work/upload/aa07.txt
#查看aa02.txt文件，内容回来了
[root@serv01 data]# cat/work/upload/aa02.txt
hello world
#恢复文件，从增量备份upload03.tar文件中来
[root@serv01 data]# tar -g flag -xPvfupload03.tar
/work/upload/
tar: Deleting `/work/upload/aa01.txt’
/work/upload/aa08.txt
[root@serv01 data]# ls /work/upload/
aa02.txt aa03.txt aa04.txt aa05.txt aa06.txt aa07.txt aa08.txt
