Linux dmesg中关于TCP: Treason uncloaked!信息
在debian Linux服务器的日志中，dmesg出现类似的信息：
TCP: Treason uncloaked! Peer 202.106.38.7:57824/80 shrinks window 3573023813:3573023814. Repaired.
TCP: Treason uncloaked! Peer 202.106.38.7:57824/80 shrinks window 3573023813:3573023814. Repaired.
TCP: Treason uncloaked! Peer 202.99.99.211:3760/80 shrinks window 1828242657:1828242673. Repaired.
TCP: Treason uncloaked! Peer 210.76.114.42:2544/80 shrinks window 504374393:504375853. Repaired.
..........
查了资料，求助了google：
That comes from the kernel tcp code below. Looks like the DLink has returned information yielding a transmit window smaller than it previously did; specifically it returned a window of zero plus an ack of up to byte 3957222360, thus indicating that it can accept nothing after that byte. Previously it had sent ome ack+wnd values indicating that it would accept up to byte 3957222379.
The Linux side is now supposed to send a packet every now and then forever until the returned window is nonzero. It does.
However, the dlink is apparently not responding in a timely manner. Any response would either open the window or update the rcv timestamp such that the thing will retransmit forever. It may be responding very slowly, or just not responding at all.
The kernel prints the message after it expected but did not see a response to the probe packet it sent to check for a nonzero window. The kernel implements exponential backoff retransmissions until it hasn't seen any response in 2m, then it will bail and close the connection. This is reasonable. It's unclear from your report if the connections are failing outright or just sometimes having to retransmit a probe against a peer that shrank the window.
结论：
The remote host decided to shrink the TCP window size without negotiating such with your Linux box. The message is of the informational level, meaning Linux doesn't like what it is seeing but will cope with it and carr
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可以将这个脚本放进crontab，他的配制文件在 /etc/crontab中每天凌晨执行一次，自动备份 这个脚本每天最多只执行一次，而且只保留最近五天的备份在服务器上。
#!/bin/bash
#This is a ShellScript For Auto DB Backup
#Powered by aspbiz
#2004-09
#Setting
#设置数据库名，数据库登录名，密码，备份路径，日志� ......
准备工作:
用到的perl 扩展组件(modules)在上篇贴出.( win32::odbc 模块
)下载组件后按照Readme文件安装倒响应目录.配置好相应的odbc数据源.
程序实现:
使用
use
Win32::ODBC;
语句包含应使用的模块是win32::odbc,写出数据库
连接字符串
$DSN = "DSN =
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linux修改主机名的方法
用hostname命令可以临时修改机器名，但机器重新启动之后就会恢复原来的值。
#hostname //查看机器名
#hostname -i //查看本机器名对应的ip地址
另外一种方法就是之久修改配置文件
修改/etc/sysconfig/network 修改这个文件，系统才有效
/etc ......
Crontab:linux计划任务。非常有用的一个命令，可以在周期性的定义一个任务的执行时间。最短的周期为1分钟。因为crontab是守护进程，每过1分钟会检查一次。
Crontab –l: 列出当前的任务列表。
Crontab –e:编辑当前的任务列表。可以通过vi编辑器来编辑任务列表。
格式如下：
分 时 日 月 周 命令
看几个例子 ......
