分类： Linux

Ubuntu Server 没有图形界面，如果作为BT 下载服务器的话，可以使用Bittorrent Transmission 来通过Web界面操作，类似http://192.168.1.X:9091这样的方式管理下载。

1.安装服务器端

sudo apt-get install transmission-daemon

2.配置文件修改

sudo vim /var/lib/transmission-daemon/info/settings.json

主要调整如下部分的内容

"rpc-enabled": true,
"rpc-password": "password",
"rpc-port": 9091,
"rpc-username": "transmission",
"rpc-whitelist": "127.0.0.1,*.*.*.*",
"rpc-whitelist-enabled": true,
 "download-dir": "/var/lib/transmission-daemon/downloads"

也就是调整白名单为所有地址都可以网络访问，同时修改用户名密码到自己熟悉的即可。其中  "download-dir" 用来调整文件下载到的地址，这个自己调整即可。

3.使得配置信息生效（注意，必须使用此命令，否则Bittorrent Transmission 会在重启的时候把数据写回磁盘，导致修改无效）

sudo service transmission-daemon reload

4.修改系统配置文件，开放对于UDP的访问限制

sudo vim /etc/sysctl.conf

增加如下语句

#udp set for Transmission
#UDP receive buffer size
net.core.rmem_max = 4194304
#UDP send buffer size
net.core.wmem_max = 1048576

然后重启服务器。

5.通过浏览器访问即可。

dante-server是一个很好的socks4/5代理服务器软件。

• 使用apt-get安装

apt-get install dante-server

• 添加一个用户

useradd proxyuser
passwd proxyuser

• 禁止proxyuser用户登录系统（安全考虑）

sudo vim /etc/passwd

将proxyuser的shell改成 /bin/false

• 配置danted.conf

sudo mv /etc/danted.conf /etc/danted.conf_old
sudo vim /etc/danted.conf

输入以下内容：

#
#logoutput: stderr
#logoutput: syslog
logoutput: /var/log/sockd/sockd.log

internal: 0.0.0.0 port = 10080

external: eth0

#method: username none
#method: pam
method: username

user.privileged: root

user.notprivileged: proxyuser

user.libwrap: nobody

compatibility: sameport
compatibility: reuseaddr
extension: bind

client pass {

        from: 0.0.0.0/0 to: 0.0.0.0/0

        log: connect disconnect error

}

pass {

        from: 0.0.0.0/0 to: 0.0.0.0/0

        command: bind

        log: connect disconnect error

}

pass {

                from: 0.0.0.0/0 to: 0.0.0.0/0

                command: bindreply udpreply

                log: connect error

}

pass {

                from: 0.0.0.0/0 to: 0.0.0.0/0 port 1-65535

                protocol: tcp udp

}

pass {

                from: 0.0.0.0/0 to: 0.0.0.0/0 port 1-65535

                command: udpassociate

}

#block {
#				from: 0.0.0.0/0 to: 0.0.0.0/0 port 1-65535
#				protocol: tcp udp
#				log: connect erro
#}

• 创建log文件夹

mkdir /var/log/sockd

• 启动dante-server

/etc/init.d/danted start

• 查看是否监听成功：

netstat -anp | grep 10080

现在你就可以使用socks5了

DELL E5400 笔记本，安装Ubuntu 13.10 ，今天突然发现，插入外置音响，耳机的时候，没有声音了，而内置的喇叭是正常的，网上查询了一下得到解决方法，目前仅仅针对IDT 92HD71B7X  芯片组，其他芯片组不保证能用。

查看声卡芯片组

cat /proc/asound/card0/codec#0 | grep Codec

输出结果如果为

Codec: IDT 92HD71B7X

则尝试本方法

sudo vim /etc/modprobe.d/alsa-base.conf

如果文件存在，则在文件的最后增加

#for Codec: IDT 92HD71B7X
options snd-hda-intel model=auto position_fix=0

重启机器，如果不想重启机器，可以尝试

sudo alsa force-reload

注意，重启，或者强制声卡重新加载之后，可能声音被强制设置为静音了，因此，需要手动打开音量，这个要注意一下。

使用Ubuntu和Fedora的用户经常会在进入GNOME时出现

Could not update /home/$USER/.ICEauthority

这样的提示。然后就不能正常进入GNOME了（之前在GNOME上的配置都消失了）

解决办法：以root的用户执行

chown $USER:$USER -R  /home/$USER/
chmod 644 /home/$USER/.ICEauthority

解决问题很简单，但为什么会出现这种情况呢？下面是我的一些个人理解

首先：先介绍下sudo和gksudo

sudo和gksudo都是使用root权限来执行应用，sudo执行程序时使用的是当前用户的配置和家目录，而gksudo使用的是root用户 的家目录和配置，一般情况下看不出什么区别，但是对于那些针对不同用户有不同的配置文件和表现形式的应用程序来说，这两种方式的结果区别就很明显了。比如 下面原文中举的firefox例子。在不通过终端运行程序时，sudo没有办法提供一个界面来输入管理员密码，比如在快捷方式中。还有些GUI程序只能用 gksudo。细心的朋友肯定发现了，在/root下并没有.ICEauthority。那么当用sudo运行程序之后，由于使用的是当前用户的配置和家 目录，

系统将整个家目录的所属者和所属组归属到root:root下，并将.ICEauthority的权限修改成600。故当再次以普通用户身份登入系统时，由于没有权限故无法读取用户的配置文件。根据上述分析，显然，当使用gksudo将能避免这种情况的发生。
一般情况下，可以这样，运行命令行程序时使用sudo，运行GUI程序时用gksudo。

下面是原文：

What’s the Issue?
Since most Ubuntu documentation asks you to use sudo even with graphical applications, I often get asked by Ubuntu users why I recommendgksudo or kdesu for graphical applications instead of sudo.

For example, a lot of guides (including the first book ever published about Ubuntu) will ask you to type this sort of command:

sudo gedit /etc/apt/sources.list

I will always recommend, however, that people use instead this sort of command:

gksudo gedit /etc/apt/sources.list

And reserve sudo for command-line applications, like so:

sudo nano /etc/apt/sources.list

Why is it an issue?
Well, to be perfectly honest, most of the time it isn’t. For a lot of applications, you can run them the improper way—using sudo for graphical applications and see no adverse side effects.

1. There are other times, though, when side effects can be as mild as Firefox extensions not sticking or as extreme as as not being able to log in any more because the permissions on your .ICEauthority changed. You can read a full discussion on the issue here.

These errors occur because sometimes when sudo launches an application, it launches with root privileges but uses the user’s configuration file.

For example, if you launch Firefox with the command

gksudo firefox

it uses root’s Firefox configuration file.

But if you launch Firefox with the command

sudo firefox

Change a few settings while launched as root, and you'll see if you dig into your Firefox profile that certain files are now owned by root.

it runs with root privileges but uses the user’s configuration file (in this case, you can see the homepage and theme are different).
2. Running graphical applications with sudo also has the downside of always having to be run from the terminal. If you don’t use the proper command—gksudo or kdesu, you will not be able to use the command as an icon launcher or keyboard shortcut because there will be no graphical dialogue box to enter your sudo password in.

3. There are also some graphical applications that simply will not run with the sudo command. Kate, for example, can be run as

kdesu kate

but cannot be run as

sudo kate

Why not make exceptions?
Bottom line: most of the time when you use sudo for graphical applications, it’s fine. Some of the time, though, it is not fine, and is, in fact, extremely bad.

If you made exceptions, you would have to give people a list of all the graphical applications that are okay to run as sudo and a list of all the graphical applications that must be run as gksudo or kdesu.

Why make a list that needs to be compiled and updated, that most people won’t refer to, and that is completely unnecessary? Just be consistent in suggesting good practice: gksudo and kdesu for graphical applications. sudo for command-line applications.

But gksudo sometimes gives me an error… even though it appears to work…

You may notice that even though gksudo is the proper way to launch graphical applications, if you launch a gksudo application it will sometimes give you what appears to be an error. This, for example:

(gedit:####): GnomeUI-WARNING **: While connecting to session manager:
Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed.

or these

Initializing nautilus-gdu extension
Nautilus-Share-Message: Called "net usershare info" but it failed: 'net usershare' returned error 255: net usershare: cannot open usershare directory /var/lib/samba/usershares. Error No such file or directory
Please ask your system administrator to enable user sharing.

That is not a real error, and there’s already been a bug report filed on the message appearing. The developers have seen the bug and labeled it a low priority. In the meantime, just ignore the message and keep encouraging people to not use sudo for graphical applications so they won’t potentially mess up their ~/.ICEauthority and other user configuration files.

参考：http://czmmiao.iteye.com/blog/1003810

top命令的TIME/TIME+是指的进程所使用的CPU时间，不是进程启动到现在的时间，因此，如果一个进程使用的cpu很少，那即使这个进程已经存在N长时间，TIME/TIME+也是很小的数值。

此外，如果你的系统有多个CPU，或者是多核CPU的话，那么，进程占用多个cpu的时间是累加的。

top的manual page：http://linux.die.net/man/1/top
看看他的帮助说明：
l: TIME — CPU Time
Total CPU time the task has used since it started. When ‘Cumulative mode’ is On, each process is listed with the cpu time that it and its dead children has used. You toggle ‘Cumulative mode’ with ‘S’, which is a command-line option and an interactive command. See the ‘S’ interactive command for additional information regarding this mode.
m: TIME+ — CPU Time, hundredths
The same as ‘TIME’, but reflecting more granularity through hundredths of a second.

参考 http://1.guotie.sinaapp.com/?p=24