BlogJava-miaoyachun-随笔分类-Linux

Install mongodb on Centos 7

Milo的海域 — Wed, 23 Mar 2016 02:14:00 GMT

介绍centos7如何安装3.0以上的新版本mongodb

https://docs.mongodb.org/manual/tutorial/install-mongodb-on-red-hat/

Milo的海域 2016-03-23 10:14 发表评论

shell中的冒号

Milo的海域 — Mon, 09 Nov 2015 07:11:00 GMT

发现一个不错的介绍shell中冒号的用法的文章

http://codingstandards.iteye.com/blog/1160298

Milo的海域 2015-11-09 15:11 发表评论

Solution of wireless link "PCI unknown" on Centos 7.1

Milo的海域 — Thu, 17 Sep 2015 02:41:00 GMT

After Centos 7.1 tobe installed on my t400, my wireless link "Intel 5100 AGN" cannot be managed by NetworkManager, which show in "PCI unknown" state.

Googled many pages, most of them introduced how to scan wifi links by command line tool "iw", i tried all steps supplied by the pages but was blocked at the last step to get dynamical ipaddress by dhclient command "sudo dhclient wlp3s0 -v". The dhclient always complain "NO DHCPOFFERS received." (I doubted there should be some tricky to play with dhclient but which i am not faimiar with.. sad.. )

But i think there would be some extending tool for NetworkManager to manager wifi, then i google "NetworkManager wifi", i got "NetwrokManager-wifi plugin" from link https://www.centos.org/forums/viewtopic.php?f=47&t=52810

After following steps , i finally make wifi work well on centos 7.1

yum install NetworkManager-wifi
reboot machine (i tried logout and login, not work)

Problem is NetworkManager-wifi is not installed by default on centos 7.1, (would it be my mistake when install OS? strange..)

Milo的海域 2015-09-17 10:41 发表评论

solution for axis2c-src-1.6.0 build failure on 64 bit ubuntu14.04s

Milo的海域 — Fri, 21 Aug 2015 03:00:00 GMT

Two compile issues i got:

One issue is:

uuid_gen_unix.c: In function 'axutil_uuid_gen_v1':uuid_gen_unix.c:62:20: error: variable 'tv' set but not used [-Werror=unused-but-set-variable] struct timeval tv; ^cc1: all warnings being treated as errors

Solution is remove "-Werror" in all configure scripts

find -type f -name configure -exec sed -i '/CFLAGS/s/-Werror//g' {} \;

Another issue is:

/usr/bin/ld: test.o: undefined reference to symbol 'axiom_xml_reader_free'
/usr/local/axis2c/lib/libaxis2_parser.so.0: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
make[4]: *** [test] Error 1
make[4]: Leaving directory `/home/miaoyachun/softwares/test/axis2c-src-1.6.0/neethi/test'

As suggested in https://code.google.com/p/staff/issues/detail?id=198, the solution is disable neethi/test in following files:

neethi/configure, remove all "test/Makefile"
neethi/Makefile.am, update "SUBDIRS = src test" with "SUBDIRS = src"
neethi/Makefile.in, update "SUBDIRS = src test" with "SUBDIRS = src"

Finally, you could run "make; sudo make install"" successfully. Last thing should be paid attention to is you may need copy all head files of neethi/include into /usr/local/axis2c/include/axis2-1.6.0/ which needed when you compile customized web service.

Enjoining it!!

Milo的海域 2015-08-21 11:00 发表评论

axis2/c的hello.c编译不过的原因

Milo的海域 — Tue, 18 Aug 2015 09:59:00 GMT

http://axis.apache.org/axis2/c/core/docs/axis2c_manual.html#client_api 的hello.c client 编译命令在我的ubuntu 12.04s上总是报错

gcc -o hello -I$AXIS2C_HOME/include/axis2-1.6.0/ -L$AXIS2C_HOME/lib -laxutil -laxis2_axiom -laxis2_parser -laxis2_engine -lpthread -laxis2_http_sender -laxis2_http_receiver -ldl -Wl,--rpath -Wl,$AXIS2C_HOME/lib hello.c
/tmp/ccCYikFh.o: In function `main':
hello.c:(.text+0x57): undefined reference to `axutil_env_create_all'
hello.c:(.text+0x68): undefined reference to `axis2_options_create'
hello.c:(.text+0x93): undefined reference to `axutil_strcmp'
hello.c:(.text+0xeb): undefined reference to `axis2_endpoint_ref_create'
hello.c:(.text+0x102): undefined reference to `axis2_options_set_to'
hello.c:(.text+0x13d): undefined reference to `axis2_svc_client_create'
hello.c:(.text+0x168): undefined reference to `axutil_error_get_message'
hello.c:(.text+0x193): undefined reference to `axutil_log_impl_log_error'
hello.c:(.text+0x1b1): undefined reference to `axis2_svc_client_set_options'
hello.c:(.text+0x1d6): undefined reference to `axis2_svc_client_send_receive'
hello.c:(.text+0x21d): undefined reference to `axiom_node_free_tree'
hello.c:(.text+0x238): undefined reference to `axutil_error_get_message'
hello.c:(.text+0x266): undefined reference to `axutil_log_impl_log_error'
hello.c:(.text+0x28d): undefined reference to `axis2_svc_client_free'
hello.c:(.text+0x2a8): undefined reference to `axutil_env_free'
/tmp/ccCYikFh.o: In function `build_om_request':
hello.c:(.text+0x2ed): undefined reference to `axiom_element_create'
hello.c:(.text+0x307): undefined reference to `axiom_element_set_text'
/tmp/ccCYikFh.o: In function `process_om_response':
hello.c:(.text+0x337): undefined reference to `axiom_node_get_first_child'
hello.c:(.text+0x351): undefined reference to `axiom_node_get_node_type'
hello.c:(.text+0x367): undefined reference to `axiom_node_get_data_element'
hello.c:(.text+0x381): undefined reference to `axiom_text_get_value'
hello.c:(.text+0x396): undefined reference to `axiom_text_get_value'
collect2: error: ld returned 1 exit status

仔细检查了gcc命令，头文件，库文件的路径都是对的，最后跟同事讨论才发现hello.c的位置的问题。。如果hello.c的位置放到了依赖库的右面就会报类似错误。但是官方的例子应该是测试过的，怎么会有这个问题呢? 难道我的ubuntu 12.04的gcc比较严格？

修正后的gcc命令如下

gcc -o hello hello.c -I$AXIS2C_HOME/include/axis2-1.6.0/ -L$AXIS2C_HOME/lib -laxutil -laxis2_axiom -laxis2_parser -laxis2_engine -lpthread -laxis2_http_sender -laxis2_http_receiver -ldl -Wl,--rpath -Wl,$AXIS2C_HOME/lib

Milo的海域 2015-08-18 17:59 发表评论

ubuntu不重启不重新登录让limit.conf文件修改立刻生效的方法

Milo的海域 — Thu, 13 Aug 2015 09:58:00 GMT

ubuntu 12.04s每次修改limit.conf文件后，要想让所有的后继ssession都能看到修改，一般要么重启系统，要么relogin系统。下面介绍一个不退出terminal就让修改立刻生效的方式

1. 修改/etc/pam.d/sudo，添加下面行到文件末尾

session required pam_limits.so

2. 修改 /etc/security/limits.conf, 比如

root soft nofile 65535
root hard nofile 65535

3. 执行sudo -i -u root 模拟登录初始化

另外发现centos 6系统/etc/pam.d/sudo已经默认enable pam_limits.so了，直接2，3就可以了。

当然如果用ssh重新登录下可能来的更快。。因为/etc/pam.d/sshd默认enable了pam_limits.so, 多输入个密码而已

Milo的海域 2015-08-13 17:58 发表评论

Ubuntu上重启ibus输入法

Milo的海域 — Wed, 17 Jun 2015 05:45:00 GMT

ubuntu上ibus经常出现不能输入中文的情况，用下面命令可以临时解决问题

ibus-daemon -r &

Milo的海域 2015-06-17 13:45 发表评论

Latency在Request/Reponse场景的定义

Milo的海域 — Tue, 01 Jul 2014 06:10:00 GMT

latency = client send request time + network trans time (->)+ server receive request time+ reponse time + server send reponse time+ network trans time (<-)+ client receive reponse time

latency = first byte out, last byte in time

Milo的海域 2014-07-01 14:10 发表评论

ubuntu 12.04的chkconfig替代品: sysv-rc-conf

Milo的海域 — Tue, 24 Dec 2013 06:54:00 GMT

以前用centos的chkconfig来管理系统服务，而ubuntu上是没有这个工具的，google上提到一个替代品sysv-rc-conf, apt-get install下就可以直接用了，有个text console可以使用

Milo的海域 2013-12-24 14:54 发表评论

关于arp_ignore

Milo的海域 — Tue, 27 Nov 2012 09:16:00 GMT

今天有同事反应一个网络现象，一个多网卡环境，发给eth1的数据包都被eth0接收了。
第一印象是arp的问题。Google了下得到了确认，有个相关的kernal参数:

arp_ignore - INTEGER
Define different modes for sending replies in response to
received ARP requests that resolve local target IP addresses:
0 - (default): reply for any local target IP address, configured
on any interface
1 - reply only if the target IP address is local address
configured on the incoming interface
2 - reply only if the target IP address is local address
configured on the incoming interface and both with the
sender's IP address are part from same subnet on this interface
3 - do not reply for local addresses configured with scope host,
only resolutions for global and link addresses are replied
4-7 - reserved
8 - do not reply for all local addresses

默认是0，解决这个问题需要配置为1

临时配置下

sysctl -w net.ipv4.conf.all.arp_ignore=1

持久配置

sysctl -w net.ipv4.conf.all.arp_ignore=1
echo 'net.ipv4.conf.all.arp_ignore=1' >> /etc/sysctl.conf

这个弄好可以重启network服务来确保其他机器更新arp cache，如果不方便重启network，自己手动敲arping命令，比如

arping -q -A -c 1 -I eth1 10.197.24.177

这个命令是在 /etc/sysconfig/network-scripts/ifup-eth里看到的

如果机器比较少，也可以直接用arp -d 来删除相关的cache，建议上面的那种发广播的方式。

Milo的海域 2012-11-27 17:16 发表评论

linux磁盘raid相关

Milo的海域 — Wed, 07 Nov 2012 05:23:00 GMT

检测磁盘相关信息

smartctl -a /dev/sda

(smartctl工具来自smartmontools, 可以apt-get install smartmontools来安装)

检测所有raid设备

mdadm -Ds

检测具体raid设备信息

mdadm -D /dev/md0

创建raid设备

mdadm --create --verbose /dev/md0 --level=raid0 --raid-devices=8 /dev/sdd /dev/sdc /dev/sdf /dev/sde /dev/sdg /dev/sdh /dev/sdi /dev/sdj

停止raid设备

mdadm -S /dev/md0

格式化raid设备

mkfs -t xfs -f /dev/md0

挂载raid设备

mount -t xfs /dev/md0 /raid

切换raid模式的步骤

    1. umount if mounted : umount /raid
    2. stop raid device: mdadm -S /dev/md0
    3. create raid: mdadm --create ...
    4. update /etc/mdadm.conf with output of 'mdadm -Ds', 用来开机自动组raid
    5. update /etc/fstab, 如果需要开机自动mount

Ref:

http://francs3.blog.163.com/blog/static/40576727201212145744783/

http://hi.baidu.com/powersaven/item/1da2dc147a8be2e25f53b19e

Milo的海域 2012-11-07 13:23 发表评论

Ubuntu上的alternatives

Milo的海域 — Fri, 26 Oct 2012 05:31:00 GMT

关于alternatives的用法

alternatives --install /usr/bin/java java /opt/jdk1.5.0_22/bin/java 15000
alternatives --install /usr/bin/javac javac /opt/jdk1.5.0_22/bin/javac 15000
alternatives --config java
alternatives --config javac

最近切换桌面环境到ubuntu, 发现alternatives这个工具改名了:update-alternatives
用法还是一样的。。

Milo的海域 2012-10-26 13:31 发表评论

用JNI从C传递结构体到JAVA

Milo的海域 — Fri, 12 Oct 2012 08:40:00 GMT

直接上C的实现

typedef struct Foo {
    int len;
    char name[100];
} Foo_t;

JNIEXPORT jint JNICALL
Java_TestJNI_foo(JNIEnv *env, jobject obj, jobject fooObj) {

    Foo_t * bar = malloc(sizeof(Foo_t));
    jclass clazz;
    jfieldID fid;

    //init the bar data of C
    strcpy(bar->name, "Yachun Miao");
    bar->len = strlen(bar->name);

    // mapping bar of C to foo
    clazz = (*env)->GetObjectClass(env, fooObj);
    if (0 == clazz) {
        printf("GetObjectClass returned 0\n");
        return (-1);
    }
    fid = (*env)->GetFieldID(env, clazz, "len", "I");
    (*env)->SetLongField(env, fooObj, fid, bar->len);

    fid = (*env)->GetFieldID(env, clazz, "name", "Ljava/lang/String;");
    jstring name = (*env)->NewStringUTF(env, bar->name);
    (*env)->SetObjectField(env, fooObj, fid, name);

    free(bar);
    return 0;
}

对应的Java调用

public class Foo {
    protected int len;
    protected String name;
}

    private static native int foo(Foo fooObj);

    public static void main(String args[]) {
        System.loadLibrary("mylib");

        Foo foo = new Foo();
        foo(foo);
        System.out.println(foo.name);
        System.out.println(foo.len);

    }

参考链接

http://www.steveolyo.com/JNI/JNI.html#CSTRCJ

http://docs.oracle.com/javase/6/docs/technotes/guides/jni/spec/types.html

Milo的海域 2012-10-12 16:40 发表评论

打通Citrix Xenapp与Citrix receiver之间的clipboard

Milo的海域 — Mon, 10 Sep 2012 07:55:00 GMT

平时要用恶心的citrix Xenapp & citrix receiver 工作环境，装完后发现client端不能复制内容到server端，这样会对工作造成很大的困扰。
偶然发现citrix receiver的进程上有个-file的选项，会指定个临时配置文件，里面提及

ClipboardAllowed=off

于是grep下这个关键字，发现~/ICAClient/linuxx86/config/All_Regions.ini 也有个类似的

ClipboardAllowed=*

改为

ClipboardAllowed=true

然后重新开Xenapp session之后发现已经可以黏贴了。

按照这个思路，使用windows的同事使用如下的方式打通两端clipboard

1. 打开系统注册表编辑器
2. 定位HKEY_CURRENT_USER\Software\Citrix\ICA Client\Engine\Lockdown Profiles\All Regions\Lockdown\Virtual Channels\Clipboard
3. 修改ClipboardAllowed为1
4. 注销当前用户（或许需要）

如果Xenapp server上使用vnc viewer之类的Xclient，如果想打通到vnc server的clipboard，还需要在vnc server所在linux主机开启以下进程

vncconfig -nowin &

这个有点不理解，但确实可行。待真相。。

Milo的海域 2012-09-10 15:55 发表评论

Ubuntu12.4上的skype不能输入中文

Milo的海域 — Tue, 04 Sep 2012 09:12:00 GMT

miaoyachun@ymiao:~$ /usr/lib/i386-linux-gnu/ibus/ibus-x11 --kill-daemon
^Z
[1]+ Stopped /usr/lib/i386-linux-gnu/ibus/ibus-x11 --kill-daemon
miaoyachun@ymiao:~$ bg
[1]+ /usr/lib/i386-linux-gnu/ibus/ibus-x11 --kill-daemon &
miaoyachun@ymiao:~$

然后就可以了。。

Milo的海域 2012-09-04 17:12 发表评论

Ubuntu12.4如何设置firefox为系统默认浏览器

Milo的海域 — Mon, 20 Aug 2012 03:28:00 GMT

今天发现ubunto12.4没有默认的浏览器，导致所有的链接打开的时候从用gedit。google上找到了解决方法:
编辑以下内容：

[Desktop Entry]
Version=14.0
Name=Mozilla Firefox Web Browser
Comment=Browse the World Wide Web
GenericName=Web Browser
Keywords=Internet;WWW;Browser;Web;Explorer
Exec=/opt/firefox/firefox %u
Terminal=false
X-MultipleArgs=false
Type=Application
Icon=firefox
Categories=GNOME;GTK;Network;WebBrowser;
MimeType=text/html;text/xml;application/xhtml+xml;application/xml;application/rss+xml;application/rdf+xml;image/gif;image/jpeg;image/png;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;x-scheme-handler/chrome;video/webm;application/x-xpinstall;
StartupNotify=true
Actions=NewWindow;

到文件~/.local/share/applications/firefox.desktop, 并保存退出。
执行：

update-desktop-database ~/.local/share/applications/

配好以后"System Settings -> Detail -> Default Applications -> Web" list里就会有firefox了。

Ref: http://askubuntu.com/questions/166455/how-do-i-make-luakit-my-default-browser

Milo的海域 2012-08-20 11:28 发表评论

eclim LocateFile not work if "invpaste" enabled in .vimrc

Milo的海域 — Mon, 06 Aug 2012 06:56:00 GMT

When play with eclim (eclipse style vim), i found its "LocateFile" command not work well when "invpaste" enabled in vim.
Solution is disable it by

" set invpaste

Milo的海域 2012-08-06 14:56 发表评论

PHP curl CURLOPT_SSL_VERIFYPEER

Milo的海域 — Tue, 17 Jul 2012 09:39:00 GMT

PHP curl option "CURLOPT_SSL_VERIFYPEER=false" is same thing of '-k or --insecure' option of curl command.

ref: http://curl.haxx.se/docs/sslcerts.html

Milo的海域 2012-07-17 17:39 发表评论

gprof call graph & memcached

Milo的海域 — Mon, 16 Jul 2012 10:03:00 GMT

assume gprof and gprof2dot.py, graphviz be installed.

1. checkout memcached src code from git server
2. sh autogen.sh & ./configure
3. modify Makefile about CFLAGS, append option '-pg', after that do make
4. run memcached & do some actions by telnet
5. terminate memcached process, a gmon.out file will be generated.
6. gprof memcached gmon.out | /usr/bin/gprof2dot.py -n0 -e0 -c bw | dot -Tpng -o memcached_callgraph.png

Milo的海域 2012-07-16 18:03 发表评论

scriptlets of RPM

Milo的海域 — Fri, 06 Jul 2012 05:41:00 GMT

The scriptlets also take an argument, passed into them by the controlling rpmbuild process. This argument, accessed via $1 is the number of packages of this name which will be left on the system when the action completes, except for %pretrans and %posttrans which are always run with $1 as 0 (%pretrans and %posttrans are available in rpm 4.4 and later). So for the common case of install, upgrade, and uninstall we have:

	install	upgrade	uninstall
%pretrans	$1 == 0	$1 == 0	(N/A)
%pre	$1 == 1	$1 == 2	(N/A)
%post	$1 == 1	$1 == 2	(N/A)
%preun	(N/A)	$1 == 1	$1 == 0
%postun	(N/A)	$1 == 1	$1 == 0
%posttrans	$1 == 0	$1 == 0	(N/A)

Scriptlets ordering

The scriptlets in %pre and %post are respectively run before and after a package is installed.
The scriptlets %preun and %postun are run before and after a package is uninstalled. The
scriptlets %pretrans and %posttrans are run at start and end of a transaction.

On upgrade, the scripts are run in the following order:

     %pretrans of new package
     %pre of new package
    (package install)
     %post of new package
     %triggerin of other packages (set off by installing new package)
     %triggerin of new package (if any are true)
     %triggerun of old package (if it's set off by uninstalling the old package)
     %triggerun of other packages (set off by uninstalling old package)
     %preun of old package
    (removal of old package)
     %postun of old package
     %triggerpostun of old package (if it's set off by uninstalling the old package)
     %triggerpostun of other packages (if they're setu off by uninstalling the old package)
     %posttrans of new package

For detail, will ref:

http://fedoraproject.org/wiki/Packaging:ScriptletSnippets

Milo的海域 2012-07-06 13:41 发表评论

Linux logrotate

Milo的海域 — Tue, 26 Jun 2012 08:07:00 GMT

1. 配置

2. 命令行选项

选项-d 用来打开debug模式
选项-v 用来打开verbose模式
选项-f 用来打开强制选项，会强制发生log rotate即使不满足条件

debug模式跟verbose的区别就是: debug模式是dry-run版本的verbose模式，一般用来调试新加的logroate配置文件, 比如：

/usr/sbin/logrotate /etc/logrotate.d/NEWCONFIG -df

/usr/sbin/logrotate /etc/logrotate.d/NEWCONFIG -vf

Milo的海域 2012-06-26 16:07 发表评论

Perlvar

Milo的海域 — Thu, 21 Jun 2012 09:10:00 GMT

Perl里面的predefined vars

perlvar

用perldoc perlvar 可以结合实例来了解更详细的信息。

下面针对$@写了个perl alarm的例子

#!/usr/bin/perl

my $timeout = 5;

$SIG{ALRM} = sub {
    die "alarm\n";
};

eval {
    alarm $timeout;
    sleep(6);
    alarm 0;
};

if ($@) {
    print "timeout\n";
}
else {
    print "not timeout\n";
}

Milo的海域 2012-06-21 17:10 发表评论

split file to pieces and restore under linux

Milo的海域 — Wed, 30 May 2012 09:38:00 GMT

Sometime mailbox disallows u upload file exceed some limitation. you can split it before upload. here is one example:

create test file

touch file1 file2;
echo 1 > file1;
echo 2 > file2;
tar zvcf old.tar.gz file1 file2;

split file to segment with size as u wished

split -b 50 old.tar.gz;

restore file from segments

cat xa* > new.tar.gz;

verify the restore

md5sum old.tar.gz new.tar.gz

Generally, the check result should be same.

Milo的海域 2012-05-30 17:38 发表评论

About cannot core dump after setuid on linux server

Milo的海域 — Wed, 30 May 2012 07:32:00 GMT

In many cases, binaries can no longer dump core after calling setuid(). 
Under Linux it is possible to re-enable this with a system call.

e.g.

+#ifdef __linux__
+#include <sys/prctl.h>
+#endif
+
#ifdef HAVE_purify
#define IF_PURIFY(A,B) (A)
#else
@@ -1362,6 +1366,10 @@
     sql_perror("setuid");
     unireg_abort(1);
   }
+#ifdef __linux__
+  /* inform kernel that process is dumpable */
+  prctl(PR_SET_DUMPABLE,1,0,0,0);
+#endif /* __linux__ */
#endif

Manual of prctl

       PR_SET_DUMPABLE
              (Since Linux 2.4) Set the state of the flag determining whether core dumps are produced for this process  upon  delivery  of  a
              signal  whose  default  behaviour  is  to  produce a core dump.  (Normally this flag is set for a process by default, but it is
              cleared when a set-user-ID or set-group-ID program is executed and also by various system calls that  manipulate  process  UIDs
              and  GIDs).  In kernels up to and including 2.6.12, arg2 must be either 0 (process is not dumpable) or 1 (process is dumpable).
              Since kernel 2.6.13, the value 2 is also permitted; this causes any binary which normally would not  be  dumped  to  be  dumped
              readable by root only.  (See also the description of /proc/sys/fs/suid_dumpable in proc(5).)



Ref: http://bugs.mysql.com/bug.php?id=21723
Some files about linux core dump:

/proc/sys/fs/suid_dumpable
/etc/profile
/etc/security/limits.conf
/proc/sys/kernel/core_pattern

Milo的海域 2012-05-30 15:32 发表评论

Use ssh-copy-id avoid inputing password

Milo的海域 — Fri, 11 May 2012 01:58:00 GMT

ssh-copy-id 避免ssh输入密码的用法：

[root@hengtiandesk118 .ssh]# ssh-copy-id -i id_rsa.pub 10.1.186.51
10
Warning: Permanently added '10.1.186.51' (RSA) to the list of known hosts.
root@10.1.186.51's password:
Now try logging into the machine, with "ssh '10.1.186.51'", and check in:

.ssh/authorized_keys

to make sure we haven't added extra keys that you weren't expecting.

[root@hengtiandesk118 .ssh]# ssh 10.1.186.51
Last login: Thu May 10 18:33:55 2012 from 10.5.4.201
[root@xen186v01 ~]#

这个脚本只要装了openssh-clients就可以用了。

以前都是手动复制粘贴的...

Milo的海域 2012-05-11 09:58 发表评论

几个ssh管道用法

Milo的海域 — Wed, 09 May 2012 09:13:00 GMT

原来ssh可以这样用

1. remote file copy

[root@xen74v01 ~]# cat test.pl
#!/usr/bin/perl
print "eth0.74"=~/(\w+)/;
print "\n";
[root@xen74v01 ~]# cat test.pl | ssh 10.1.74.76 'cat - > /tmp/test.pl'

拷贝文件时，如果文件很大，又不想影响网络IO可以用pv工具进行流量控制

pv -L10m test.pl | ssh 10.1.74.76 'cat - > /tmp/test.pl'

这里pv的行为跟cat比较类似，但是支持IO流量控制，这里设置10M/s.

2. local script remote execute

[root@xen74v01 ~]# cat test.pl
#!/usr/bin/perl
print "eth0.74"=~/(\w+)/;
print "\n";
[root@xen74v01 ~]# perl test.pl
eth0
[root@xen74v01 ~]# cat test.pl | ssh 10.1.74.76 'perl'
eth0
[root@xen74v01 ~]# ssh 10.1.74.76 'perl' < test.pl
eth0

这样就不用把脚本拷贝到远端去执行了

参考：

http://linux.icydog.net/ssh/piping.php

http://www.ivarch.com/programs/quickref/pv.shtml

http://www.mysqlperformanceblog.com/2009/05/20/hint-throttling-xtrabackup/

Milo的海域 2012-05-09 17:13 发表评论

Notes for SNMP

Milo的海域 — Mon, 07 May 2012 08:57:00 GMT

1. Tutorial
http://net-snmp.sourceforge.net/wiki/index.php/Tutorials

2. Config & start agent
snmpconf

3. snmpwalk example

snmpwalk -v2c -c public 10.1.74.51

4. check MIB modules

snmptranslate -Dinit_mib .1.3 2>&1 |grep MIBDIR

5. extending MIB Module
http://net-snmp.sourceforge.net/wiki/index.php/TUT:Writing_a_MIB_Module
   a. download net-snmp src code
   b. MIB definition
   c. mib2c (in net-snmp-perl)
   d. make & make install
   e. edit snmpd conf & restart agent
   f. snmpwalk to verify

Milo的海域 2012-05-07 16:57 发表评论

Use iozone to test file system performance

Milo的海域 — Thu, 26 Apr 2012 02:49:00 GMT

iozone 是一个开源的文件系统benchmark 测试工具。可用来检测当前或者指定磁盘的读写性能。

http://www.iozone.org/

安装

先确保rpmforge repository源已经安装。具体参考：
http://www.blogjava.net/miaoyachun/archive/2012/02/03/369319.html

然后直接yum安装

yum install iozone

测试

iozone  -i 0 -r 32 -s 2097152
        Iozone: Performance Test of File I/O
                Version $Revision: 3.394 $
                Compiled for 64 bit mode.
                Build: linux

        Contributors:William Norcott, Don Capps, Isom Crawford, Kirby Collins
                     Al Slater, Scott Rhine, Mike Wisner, Ken Goss
                     Steve Landherr, Brad Smith, Mark Kelly, Dr. Alain CYR,
                     Randy Dunlap, Mark Montague, Dan Million, Gavin Brebner,
                     Jean-Marc Zucconi, Jeff Blomberg, Benny Halevy, Dave Boone,
                     Erik Habbinga, Kris Strecker, Walter Wong, Joshua Root,
                     Fabrice Bacchella, Zhenghua Xue, Qin Li, Darren Sawyer.
                     Ben England.

        Run began: Wed Apr 25 19:36:55 2012

        Record Size 32 KB
        File size set to 2097152 KB
        Command line used: iozone -i 0 -r 32 -s 2097152
        Output is in Kbytes/sec
        Time Resolution = 0.000001 seconds.
        Processor cache size set to 1024 Kbytes.
        Processor cache line size set to 32 bytes.
        File stride size set to 17 * record size.
                                                            random  random    bkwd   record   stride
              KB  reclen   write rewrite    read    reread    read   write    read  rewrite     read   fwrite frewrite   fread  freread
         2097152      32  844758 2001670

iozone test complete.

Milo的海域 2012-04-26 10:49 发表评论