Shulou(Shulou.com)06/02 Report--

What you see, update for a long time.

1.linux garbled problem

[root@vps software] # vi / etc/sysconfig/i18n

LANG='zh_CN.utf8'

SYSFONT=latarcyrheb-sun16

SUPPORTED= "zh_CN.UTF-8:zh_CN:zh"

LANG variable is the abbreviation of language. Users with a little English foundation can see that this variable determines the default language of the system, that is, the menu of the system, the toolbar language of the program, the default language of input method, and so on.

SYSFONT is short for system font, which determines which font the system uses by default.

The SUPPORTED variable determines the language that the system supports, that is, the language that the system can display.

[root@vps software] # source / etc/sysconfig/i18n

two。 Time synchronization

[root@vps /] # crontab-l

01 01 * / usr/sbin/ntpdate cn.pool.ntp.org; hwclock-w > > / dev/null 2 > & 1

Hwclock-w synchronization to hardware clock

3. View 80 connections

[root@vps /] # netstat-n | grep: 80 | awk'/ ^ tcp/ {+ + S [$NF]} END {for (an in S) print a, S [a]}'

TIME_WAIT 2

CLOSE_WAIT 136

ESTABLISHED 3

4. Mirror image problem

Error: Cannot retrieve metalink for repository: epel. Please verify its path and try again

Solution: edit / etc/yum.repos.d/epel.repo, comment out the basic recovery and the address of the image

# baseurl

Mirrorlist

Change to

Baseurl

# mirrorlist

5.yum cannot be used, lack of package

[root@Monitor lib] # yum install fping

There was a problem importing one of the Python modules

Required to run yum. The error leading to this problem was:

Libcurl.so.4: cannot open shared object file: No such file or directory

Please install a package which provides this module, or

Verify that the module is installed correctly.

It's possible that the above module doesn't match the

Current version of Python, which is:

2.6.6 (r266 84292, Jan 22 2014, 09:42:36)

[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)]

If you cannot solve this problem yourself, please go to

The yum faq at:

Http://yum.baseurl.org/wiki/Faq

Https://pkgs.org/centos-6/centos-x86_64/libcurl-7.19.7-52.el6.x86_64.rpm.html

Libcurl-7.19.7-52.el6.x86_64.rpm

Zlib-1.2.3-29.el6.x86_64.rpm

6. Install the graphical interface

Yum-y groupinstall Desktop

Yum-y groupinstall "X Window System"

Yum-y groupinstall chinese-support

Startx

7.java environment variable setting

[root@Monitor ~] # yum-y install java-1.7.0-openjdk*

[root@Monitor ~] # java-version

Java version "1.7.0,111"

OpenJDK Runtime Environment (rhel-2.6.7.2.el6_8-x86_64 u111-b01)

OpenJDK 64-Bit Server VM (build 24.111-b01, mixed mode)

[root@Monitor ~] # export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk.x86_64

The java environment variable sets http://blog.csdn.net/u010440155/article/details/51544282

8.tomcat java memory Settings

Catalina.sh:

JAVA_OPTS='-server-Xms10240m-Xmx10240m-XX:NewSize=512m-XX:MaxNewSize=512m-XX:PermSize=128m-XX:MaxPermSize=128m'

Xms: jvm startup memory defaults to 1x64 of physical memory

Maximum memory allocated during Xmx:jvm operation

If the remaining memory is less than 40%, the JVM will increase the heap to the value set by Xmx, and if the remaining memory is more than 70%, the JVM will reduce the heap to the value set by Xms.

If the Xms exceeds the XMX value, or if the sum of the heap maximum and non-heap maximum exceeds the physical memory or operating system maximum limit, the server will not start.

Set NewSize and MaxNewSize to be equal, and the size of "new" should not be more than half of that of "old". This is because if the old area does not trigger the "main" GC frequently, the performance will be greatly reduced.

9. Manually free memory

Http://lizhenliang.blog.51cto.com/7876557/1657448

Sync

Echo 1 > / proc/sys/vm/drop_caches

The value of drop_caches can be a number between 0 and 3, representing different meanings:

0: no release (system default)

1: release the page cache

2: release dentries and inodes

3: release all caches

10. Linux records user actions in detail

Http://369369.blog.51cto.com/319630/1732164

Modify the / etc/profile file and add the following at the end:

# history

Export HISTTIMEFORMAT= "[% Y%m%d-%H%M-:%S]"

USER_IP= `who-u am i 2 > / dev/null | awk'{print$NF}'| sed-e's / [()] / / g``

HISTDIR=/var/log/history

If [- z $USER_IP]

Then

USER_IP= `hostname`

Fi

If [!-d $HISTDIR]

Then

Mkdir-p $HISTDIR

Chmod 777$ HISTDIR

Fi

If [!-d $HISTDIR/$ {LOGNAME}]

Then

Mkdir-p $HISTDIR/$ {LOGNAME}

Chmod 300$ HISTDIR/$ {LOGNAME}

Fi

Export HISTSIZE=1000

DT= `date +% Y% m% dice% H% M% S`

Export HISTFILE= "$HISTDIR/$ {LOGNAME} / ${USER_IP} .hist. $DT"

Chmod 600$ HISTDIR/$ {LOGNAME} / * .hist* 2 > / dev/null

# history end

11. How does linux mount the shared directory under windows?

Mount-t cifs-o username=windows login account, password= "password corresponding to windows account" / / 16.187.190.50/test / mnt/linux destination folder

Or muout.cifs / / native IP address / test / mut/linux destination folder-o username= "windows login account", password= "password corresponding to the windows account"

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