13.1、rsync简介
rsync(remote synchronize)是一个远程数据同步工具，可以通过LAN/WAN快速同步多台主机之间的文件。也可以使用rsync同步本地磁盘中的不同目录。在使用rsync进行远程同步时，可以使用两种方式：远程shell方式和C/S方式。无论本地同步目录还是远程同步数据，首次运行时将会把全部文件复制一次，以后再运行时将只复制有变化的文件或文件的变化部分。
实施备份时有两种情况：
1、需要保留备份历史归档，在备份时保留历史的备份归档，是为了在系统出现错误后能恢复到当前的状态，这可以使用完全备份和增量备份来完成。 可以使用tar命令保存归档文件 为了提高备份效率，也可以使用rsync结合tar来完成 2、无需保留备份历史归档，则只需要备份系统最‘新鲜’的状态，这可以使用rsync同步来完成，此时通常称为镜像。镜像可以分为两种： 被镜像的目录在各个主机上保存相同的位置，此时一般是为了实施负载均衡而对多个主机进行同步镜像； 被镜像的目录在哥哥主机上不保持相同的位置。
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rsync命令
rsync是一个功能强大的工具，其命令也有很多功能选项，其命令格式为：
本地使用： Local: rsync [OPTION...] SRC... [DEST] 远程shell模式，此时可以利用ssh协议承载其数据传输过程： Pull: rsync [OPTION...] [USER@]HOST:SRC... [DEST] Push: rsync [OPTION...] SRC... [USER@]HOST:DEST 服务模式，此时rsync工作为守护进程，能接收客户端的数据同步请求 Pull: rsync [OPTION...] [USER@]HOST::SRC... [DEST] rsync [OPTION...] rsync://[USER@]HOST[:PORT]/SRC... [DEST] Push: rsync [OPTION...] SRC... [USER@]HOST::DEST rsync [OPTION...] SRC... rsync://[USER@]HOST[:PORT]/DEST
其中：
SRC： 要复制的源位置
DEST：复制目标位置
若本地登录用户与远程主机上的用户一致，可以省略USER@
使用远程shell同步时，主机名与资源名之间用‘:‘作为分隔符
使用rsync服务器同步时，主机名与资源名之间用‘::‘作为分隔符
pull，‘拉‘是指从远程主机复制文件到本地主机
push，‘推‘是指从本地主机复制文件到远程主机
当进行‘拉‘复制时，若指定一个SRC且省略DEST，则只列出资源而不复制
注意：rsync命令中，如果源路径是目录，且给复制路径时末尾有/，则会复制目录中的内容，而非目录本身；如果末尾没有/，则会同步目录本身及目录中的所有文件；目标路径末尾是否有/无关紧要。
rsync常用选项：
-n: 同步测试，不执行真正的同步过程； -v: --verbose详细输出模式 -q: --quiet，静默模式 -c: --checksum开启校验功能 -r: --recursive递归复制； -a: --archives归档保留文件的原有属性 -p: --perms 保留文件的权限 -t: --times 保留文件的时间戳 -l: --links 保留文件的符号链接 -g: --group 保留文件的属组 -o: --owner 保留文件的属主 -D:--devices 保留设备文件 -e ssh: 表示使用ssh协议作承载 -z: 对文件压缩后传输 --progress：显示进度条 --stats: 显示如何执行压缩和传输 --delete：删除那些接收端还保留，而发送端已经不存在的数据 |
rsync的基本使用
本地磁盘同步数据：
[root@localhost ~]# ls /home/ #本地磁盘数据 samba-4.6.5 samba-4.6.5.tar.gz [root@localhost ~]# rsync -a --delete /home /backups/ #将整个/home目录复制到目标目录 [root@localhost ~]# ls /backups/ home [root@localhost ~]# rsync -a --delete /home/ /backups/#将/home目录中内容复制到目标目录 [root@localhost ~]# ls /backups/ samba-4.6.5 samba-4.6.5.tar.gz
使用基于ssh的rsync远程同步数据：
[root@localhost ~]# rsync /etc/hosts 192.168.191.129:/etc/hosts #执行推同步 root@192.168.191.129‘s password: [root@localhost ~]# rsync 192.168.191.129:/etc/hosts /etc/hosts #执行拉同步 root@192.168.191.129‘s password:
13.2、配置rsync以daemon方式运行
1、设定rsync服务器端
1) 安装并启动xinetd
[root@localhost ~]# yum -y install xinetd rsync
2) 为rsync服务提供配置文件/etc/rsyncd.conf
[root@localhost ~]# vim /etc/rsyncd.conf # Global Settings uid = nobody #以什么身份运行进程 gid = nobody use chroot = no max connections = 10 strict modes = yes pid file = /var/run/rsyncd.pid log file = /var/log/rsyncd.log list = yes # Directory to be synced [synced_name] path = /home/ ignore errors = yes read only = no write only = no list = false uid = root #以什么身份获取文件 gid = root auth users = username secrets file = /etc/rsyncd.passwd #用户账号验证文件 hosts allow = 192.168.191.129 hosts deny = *
权限说明：
1、二者都不出现时，默认为允许访问； 2、只出现hosts allow: 白名单；但没有被匹配到的主机默认处理，允许； 3、只出现hosts deny：黑名单；出现在名单中的都被拒绝； 4、二者同时出现：先检查hosts allow，匹配到就allow，否则，检查hosts deny，匹配则拒绝；如二者均无匹配，则由默认规则处理，即为允许； |
3) 配置密码文件/etc/rsyncd.passwd
文件格式(明文)：username:password (文件权限要设置为600)
[root@localhost ~]# vim /etc/rsyncd.passwd mylinux:123 [root@localhost ~]# chmod 600 /etc/rsyncd.passwd
4) 配置服务能够启动
[root@localhost ~]# chkconfig rsync on [root@localhost ~]# service xinetd start #监听端口tcp/873 Starting xinetd: [ OK ] [root@localhost ~]# setenforce 0 #关闭selinux，很关键
2、在客户端做测试
[root@localhost ~]# rsync --list-only rsync://mylinux@192.168.191.128/home #查看列表 Password: drwxr-xr-x 4096 2017/06/15 18:06:02 . -rwxr-xr-x 21111639 2017/06/06 15:50:37 samba-4.6.5.tar.gz drwxr-xr-x 4096 2017/06/15 18:06:02 mylinux drwxr-xr-x 4096 2017/06/13 17:28:15 samba-4.6.5 [root@localhost ~]# rsync -avzP --delete mylinux@192.168.191.128::home /backups/ Password: #简单同步，不保存历史文档 receiving incremental file list ./ mylinux/ mylinux/.bash_logout 18 100% 17.58kB/s 0:00:00 (xfer#1, to-check=1013/1018) mylinux/.bash_profile 176 100% 85.94kB/s 0:00:00 (xfer#2, to-check=1012/1018) mylinux/.bashrc 124 100% 60.55kB/s 0:00:00 (xfer#3, to-check=1011/1018) sent 45978 bytes received 453928 bytes 199962.40 bytes/sec total size is 470170720 speedup is 940.52 [root@localhost ~]# ls /backups/ #备份的文件 mylinux samba-4.6.5 samba-4.6.5.tar.gz
13.3、inotify简单介绍
inotify是linux内核特性，它监控文件系统并及时项专门的应用程序发出相关事件的警告。如：读、写、删除、备份等。其操作工具为inotify-tools。要使用 inotify，必须具备一台带有2.6.13 或更新内核的 Linux 机器（以前的 Linux 内核版本使用更低级的文件监控器dnotify）。
[root@localhost ~]# uname -a #查看内核版本 Linux contos 2.6.32-431.el6.x86_64 #1 SMP Fri Nov 22 03:15:09 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux [root@localhost ~]# ls -l /proc/sys/fs/inotify/ #查看是否支持inotify total 0 -rw-r--r-- 1 root root 0 Jun 15 21:09 max_queued_events #inotify队列最大长度 -rw-r--r-- 1 root root 0 Jun 15 21:09 max_user_instances #每个用户创建inotify实例最大值 -rw-r--r-- 1 root root 0 Jun 15 21:09 max_user_watches #要同步的文件包含的目录数 [root@localhost home]# wget #下载 inotify-tools源码包 [root@localhost home]#tar xf inotify-tools-3.14.tar.gz [root@localhost home]#cd inotify-tools-3.14 [root@localhost inotify-tools-3.14]./configure --prefix=/usr/local/inotify-tools [root@localhost inotify-tools-3.14]make && make install
在inotify-tools工具包中有两个工具inotifywait和inotifywatch。
inotifywait：在被监控的文件系统或目录上等待特定文件系统事件(open、close、delete等)。执行后处于阻塞状态，适合脚本中使用。 inotifywatch：收集被监视文件系统使用时数据统计、指文件系统事件发出次数统计。 |
inotifywait [-cmrq] [-e <event> ] [-t <seconds> ] [--format <fmt> ][--timefmt <fmt> ] <file> #inotifywait语法格式
常用参数：
--timefmt 时间格式 %y年 %m月 %d日 %H小时 %M分钟 --format 输出格式 %T时间 %w路径 %f文件名 %e状态 -m 始终保持监听状态，默认触发事件即退出。 -r 递归查询目录 -q 打印出监控事件 -e 定义监控的事件，可用参数： open 打开文件 access 访问文件 modify 修改文件 delete 删除文件 create 新建文件 attrb 属性变更 Options: -h|--help Show this help text. @<file> Exclude the specified file from being watched. --exclude <pattern> Exclude all events on files matching the extended regular expression <pattern>. --excludei <pattern> Like --exclude but case insensitive. -m|--monitor Keep listening for events forever. Without this option, inotifywait will exit after one event is received. -d|--daemon Same as --monitor, except run in the background logging events to a file specified by --outfile. Implies --syslog. -r|--recursive Watch directories recursively. --fromfile <file> Read files to watch from <file> or `-‘ for stdin. -o|--outfile <file> Print events to <file> rather than stdout. -s|--syslog Send errors to syslog rather than stderr. -q|--quiet Print less (only print events). -qq Print nothing (not even events). --format <fmt> Print using a specified printf-like format string; read the man page for more details. --timefmt <fmt> strftime-compatible format string for use with %T in --format string. -c|--csv Print events in CSV format. -t|--timeout <seconds> When listening for a single event, time out after waiting for an event for <seconds> seconds. If <seconds> is 0, inotifywait will never time out. -e|--event <event1> [ -e|--event <event2> ... ] Listen for specific event(s). If omitted, all events are listened for. Exit status: 0 - An event you asked to watch for was received. 1 - An event you did not ask to watch for was received (usually delete_self or unmount), or some error occurred. 2 - The --timeout option was given and no events occurred in the specified interval of time. Events: access file or directory contents were read modify file or directory contents were written attrib file or directory attributes changed close_write file or directory closed, after being opened in writeable mode close_nowrite file or directory closed, after being opened in read-only mode close file or directory closed, regardless of read/write mode open file or directory opened moved_to file or directory moved to watched directory moved_from file or directory moved from watched directory move file or directory moved to or from watched directory create file or directory created within watched directory delete file or directory deleted within watched directory delete_self file or directory was deleted unmount file system containing file or directory unmounted |
inotifywatch [ options ] file1 [ file2 ] [ ... ] #inotifywatch语法格式
Options: -h|--help Show this help text. -v|--verbose Be verbose. @<file> Exclude the specified file from being watched. --fromfile <file> Read files to watch from <file> or `-‘ for stdin. --exclude <pattern> Exclude all events on files matching the extended regular expression <pattern>. --excludei <pattern> Like --exclude but case insensitive. -z|--zero In the final table of results, output rows and columns even if they consist only of zeros (the default is to not output these rows and columns). -r|--recursive Watch directories recursively. -t|--timeout <seconds> Listen only for specified amount of time in seconds; if omitted or 0, inotifywatch will execute until receiving an interrupt signal. -e|--event <event1> [ -e|--event <event2> ... ] Listen for specific event(s). If omitted, all events are listened for. -a|--ascending <event> Sort ascending by a particular event, or `total‘. -d|--descending <event> Sort descending by a particular event, or `total‘. Exit status: 0 - Exited normally. 1 - Some error occurred. Events: access file or directory contents were read modify file or directory contents were written attrib file or directory attributes changed close_write file or directory closed, after being opened in writeable mode close_nowrite file or directory closed, after being opened in read-only mode close file or directory closed, regardless of read/write mode open file or directory opened moved_to file or directory moved to watched directory moved_from file or directory moved from watched directory move file or directory moved to or from watched directory create file or directory created within watched directory delete file or directory deleted within watched directory delete_self file or directory was deleted unmount file system containing file or directory unmounted |
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原文地址：http://yinsuifeng.blog.51cto.com/10173491/1937023
