linux-admin

2017年6月2日
分类于 cloud-infra, linux-admin, draft
需要 1 分钟阅读时间

虚拟化平台镜像去冗测试（opendedup）

OpenDedup，是一款开源去重文件系统，https://github.com/opendedup/sdfs，可以分布式，支持NFS、iSCSI等，感觉非常厉害，作者是Veritas的银堡（Sam Silverberg）。

Note

RedHat 7就开始带了VDO，但是还没测过。

可以去官网下载镜像，或者是笔者认为更加实用的NAS系统。

简单测试

目的是减少更多本地环境占用，使用opendedup测试。

首先测试我新闻服务器上的数据，以索引文件为主，经常变动，有大有小。
然后选择一款kvm软件平台。

安装：

wget http://www.opendedup.org/downloads/sdfs-latest.deb
sudo dpkg -i sdfs-latest.deb

sudo su
echo "* hardnofile 65535" >> /etc/security/limits.conf
echo "* soft nofile 65535" >> /etc/security/limits.conf
exit
sudo mkfs.sdfs --volume-name=pool0 --volume-capacity=256GB
sudo mkdir /media/pool0 
sudo mount.sdfs pool0 /media/pool0/

数据拷贝进去后，原9.3GB索引数据降为8.5GB，效果不如想象中好。

可能原因：

sdfs提供了丰富的命令行选项，我没有使用，使用后可能会达到预期，比如更小的block。

2013年4月15日
分类于 ai, linux-admin, others
需要 1 分钟阅读时间

Rex设计

目前已完成 capture，dlayer和tlayer。 IplImage 和 Mat转换可考虑不用了在写交互的部分，后期完成可能会用gtk。需要的传感器：加速度（FPV向） ROI：移动检测抛弃gtk（时间长，没意思），转用ncurses

2012年9月18日
分类于 linux-admin
需要 9 分钟阅读时间

实用笔记

cmake 配置安装完opencv后，将安装路径中到lib/pkg-config/opencv.pc复制到/usr/lib/pkg-config，然后可以进行pkg-config 查找

gnome3任务栏快捷方式的存放位置拖到浏览器或者终端里你就看见了。。

curl POST

curl -X POST -d '4142430A02000' http://user:pass@myhost/hudson/job/_jobName_/postBuildResult

curl -X POST -d @myfilename http://user:pass@myhost/hudson/job/_jobName_/postBuildResult

ddwrt 内网不能访问内网域名

iptables -t nat -I POSTROUTING -o br0 -s 192.168.0.188/24 -d 192.168.0.188/24 -j MASQUERADE

vpn的内网的问题

iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j SNAT --to-source 70.8.7.6

iptables -t nat -A POSTROUTING -o eth0 -s 172.16.1.0/24 -j MASQUERADE

!/bin/bash

livecd-creator --config=/usr/share/spin-kickstarts/fedora-livecd-desktop.ks \ --fslabel=Test \ --tmpdir=/root/iso/tmp \ --cache=/root/iso/cache \ --nocleanup \ --cacheonly #为节约下载时间可在以后制作时忽略

mysql grant

grant all privileges on *.* to root@'%' identified by '123456'; flush privileges;

打开kvm nested参数

cat /sys/module/kvm_intel/parameters/nested

为N则

modprobe -r kvm-intel modprobe kvm-intel nested=1

Fedora滚动升级版 Rawhide

yum install fedora-release-rawhide yum-config-manager --disable fedora updates updates-testing yum-config-manager --enable rawhide yum update yum yum --releasever=rawhide distro-sync --nogpgcheck

or

dnf upgrade --refresh dnf install dnf-plugin-system-upgrade dnf system-upgrade download --refresh --releasever=rawhide --allowerasing dnf system-upgrade reboot

zypper ar --refresh http://download.opensuse.org/repositories/openSUSE:/Tumbleweed/standard/ Tumbleweed zypper ar --refresh http://download.opensuse.org/distribution/openSUSE-current/repo/oss/ 'openSUSE Current OSS' zypper ar --refresh http://download.opensuse.org/distribution/openSUSE-current/repo/non-oss/ 'openSUSE Current non-OSS' zypper ar --refresh http://download.opensuse.org/update/openSUSE-current/ 'openSUSE Current updates' zypper ar --refresh http://download.opensuse.org/update/openSUSE-non-oss-current/ 'openSUSE Current non-OSS updates' zypper dup

vs2012修复补丁

由于升级.net 4.5会出现vs2012部分项目失败，可以打这个补丁修复 Microsoft Visual Studio 2012 更新 (KB2781514)

RESTClient

针对RESTful的API可以使用这个工具 http://restclient.org

dl-ssl.google.com

74.125.237.1

owncloud repo

http://software.opensuse.org/download/package?project=isv:ownCloud:devel&package=owncloud-client

android google play

cp /data/app/googleplay /system/app/

获取Gravatar头像

curl http://www.gravatar.com/avatar/`echo -n [email protected] | md5sum` > gravatar.jpg

Maven insecure SSL

-Dmaven.wagon.http.ssl.insecure=true -Dmaven.wagon.http.ssl.allowall=true

bVNC build

FreeRDP: checkout dbbb341; cmake .; ant release Singed keystore: keytool -genkey -alias android.keystore -keyalg RSA -validity 20000 -keystore android.keystore http://www.mail-archive.com/[email protected]/msg13763.html

IPA ADD-USER

!/bin/bash

echo -e "pswd4admin\n" | kinit admin echo -e "$1\\n$1\n$1\\n" | ipa user-add echo -e "$1\n$1\\n" | ipa passwd \(1 sleep 1 echo -e "$1\\n\)1\n$1\n" | kinit $1

NTP server

server 192.168.1.11 mask 255.255.0.0 nomodify 启动ntpd后要等个几分钟，client才能去同步，否则报错说未找到合适的ntp服务器

rsync

rsync -zvrtopgal -e ssh --delete --stats --progress --exclude 'ignore.txt' [email protected]:/var/log /home/lofyer/lofyer.org/

CentOS Smartcard

SmartCard service: openct pcscd

zathura

很好的PDF阅读器

ssh without password

Generate rsa key pair without passphrase

[demo@A ~]$ ssh-keygen -t rsa

Copy pub key to B

[demo@A ~]$ cat .ssh/id_rsa.pub | ssh alpha@B 'cat >> .ssh/authorized_keys2'

Add private key to A

[demo@A ~]$ ssh-add ~/.ssh/id_rsa or just [demo@A ~]$ ssh-copy-id alpha@B

ssh to a new host without key checking promption

vim /etc/ssh/ssh_config

... StrictHostKeyChecking no ...

debian offcie乱码

安装文泉逸字体 apt-get install fonts-wenquanyi

debian virt-viewer with spice

deb http://mirrors.163.com/debian/ unstable main deb-src http://mirrors.163.com/debian/ unstable main

deb http://security.debian.org/ unstable/updates main deb-src http://security.debian.org/ unstable/updates main

unstable-updates, previously known as 'volatile'

deb http://mirrors.163.com/debian/ unstable-updates main deb-src http://mirrors.163.com/debian/ unstable-updates main deb http://apt.wxwidgets.org/ unstable-wx main deb-src http://apt.wxwidgets.org/ unstable-wx main

Better DNS

dns1: 199.91.73.222 dns2: 8.8.8.8

audit log

Modify /etc/audit/audit.conf to 8192 or bigger.

memcached

PHP

apt-get install memcached php5-memcached

modify /etc/php5/conf.d/memcached.ini

disable TSO GSO to improve virtio-net

ethtool -K eth0 gso off

ethtool -K eth0 tso off

disable PackageKit in Fedora

/etc/yum/pluginconf.d/refresh-packagekit.conf

enabled=0

crt & key to pem

openssl x509 -inform DER -outform PEM -in server.crt -out server.crt.pem openssl rsa -inform DER -outform PEM -in server.key -out server.key.pem cat server.crt.pem server.key.pem >> server.pem

wireless relay for tomata

设置无线中继时确保主路由和从路由的SSID、密码、加密方式一致，不要使用WPA/WPA-2混合模式

libvirt password

saslpasswd2 -a libvirt root

netcat(nc) tips

大传输文件(file transfer)

server: nc -l 5555 < file_to_copy client: nc server_ip 5555 > new_file

聊天(chat)

client1: nc -l 5555 client2: nc server_ip 5555

udp connection

server: nc -4 -u -l 5555 clinet: nc -4 -u localhost 5555

owncloud repo

[isv_ownCloud_community] name=Latest stable community release of ownCloud (CentOS_CentOS-6) type=rpm-md baseurl=http://download.opensuse.org/repositories/isv:/ownCloud:/community/CentOS_CentOS-6/ gpgcheck=1 gpgkey=http://download.opensuse.org/repositories/isv:/ownCloud:/community/CentOS_CentOS-6/repodata/repomd.xml.key enabled=1

gnome terminal proxy

$ ssh -ND 7070 yourname@yourserver $ gconftool-2 -R /system/proxy # show configuration $ gconftool-2 -s /system/proxy/socks_host -t int 127.0.0.1 $ gconftool-2 -s /system/proxy/socks_port -t int 7070 $ gconftool-2 -s /system/proxy/mode -t string manual # enable $ gconftool-2 -s /system/proxy/mode -t string none # disable

update xcode cmd

xcode-select --install

Test linux watchdog

echo c > /proc/sysrq-trigger

Bash环境变量漏洞检测

env x='() { :;}; echo asdasd' bash -c "echo asd"

maven socks5 proxy

-DsocksProxyHost=127.0.0.1 -DsocksProxyPort=7070

When your vm has 2 ethernet, DO noticed which one is the default gateway, or you will fail in ROUTER PORT FORWARDING.

Delete RAID info in your disk

dmraid -n /dev/sda

DDF1 Anchor at 12345678

dd if=/dev/zero of=/dev/sda seek=12345678 bs=512 count=1

Postgresql recovery when xlog failed

$ pg_resetxlog -f -x 0x9A00000 -m 0x10000 -O 0x10000 -l 0x1,0xB67,0x58 -D /var/lib/pgsql/data or $ pg_resetxlog -f /var/lib/pg_sql/data Transaction log reset

解决mysql＋php中文显示问号问题

比如在vtigercrm，zabbix中

创建utf8排序的数据库即可

mysql

create database mydb DEFAULT CHARSET utf8 COLLATE utf8_general_ci;

Mysql delete duplicated rows

delete from posts where id not in (select * from (select max(n.id) from posts n group by n.title) x);

OR

create table new as select * from posts where 1 group by url; rename table new master;

pip upgrade all

pip freeze --local | grep -v '^\-e' | cut -d = -f 1 | xargs -n1 pip install -U

wget 递归下载

wget -c -r -np -k -L -p http://example.com/dir0/

修改gem源

$ gem sources --remove https://rubygems.org/ $ gem sources -a https://ruby.taobao.org/ $ gem sources -l *** CURRENT SOURCES ***

https://ruby.taobao.org

请确保只有 ruby.taobao.org

使用extundelete恢复rm -fr数据

从http://extundelete.sourceforge.net/下载源码，安装efs2progs-devel并编译。

mount /dev/sdb2 /mnt -o ro

extundelete /dev/sdb2 --restore-files relative-path-to-files --after 20140404

OR

extundelete /dev/sdb2 --restore-all

使用TestDisk/PhotoRec恢复分区/数据

从http://www.cgsecurity.org/wiki/TestDisk下载TestDisk，解压后会发现源码以及静态编译文件，直接执行即可，其中TestDisk恢复分区，PhotoRec恢复图片文件。

Wordpress 摘要字数搜索关键字excerpt_length

Eclipse multiuser

Add following code to your eclipse/configuration/config.ini

[email protected]/Eclipse/configuration osgi.sharedConfiguration.area=/opt/eclipse/configuration osgi.configuration.cascaded=true

get cer and key out of pfx

openssl pkcs12 -in domain.pfx -clcerts -nokeys -out domain.cer openssl pkcs12 -in domain.pfx -nocerts -nodes -out domain.key

openssl/gpg encrypt/decrypt

$ echo Hi | openssl enc -aes-128-cbc -a -salt -pass pass:wtf U2FsdGVkX18qAdhqop1SffsewHue6EOPNKv9dXc/0rI= $ echo U2FsdGVkX18qAdhqop1SffsewHue6EOPNKv9dXc/0rI= | openssl enc -aes-128-cbc -a -d -salt -pass pass:wtf Hi

OR

generate a 2048-bit RSA key and store it in key.txt

openssl genrsa -out key.txt 2048

encrypt "hello world" using the RSA key in key.txt

echo "hello world" | openssl rsautl -inkey key.txt -encrypt >output.bin

decrypt the message and output to stdout

openssl rsautl -inkey key.txt -decrypt OR

gpg --encrypt -r [email protected] >tempfile gpg --decrypt

ssh port forward

(localpc)$ ssh -g -L 2222:localhost:22 [email protected]

ssh to localhost:2222 to connect lofyer.org

(localpc)$ ssh -lroot -p 2222 localhost

Remote Forwarding

(localpc)$ ssh -R -L 2222:localhost:22 [email protected]

On host lofyer.org, ssh to localhost:2222 to connect localpc.

(lofyer.org)$ ssh localhost -p 2222

Mixed, localpc:22->lofyer.org:2222

On lofyer.org we make a tunnel(2222) to localpc:22

(localpc)$ ssh -R 2222:localhost:22 lofyer.org

Make a local tunnel(3333) listening on all interface to localpc:2222

(lofyer.org)$ ssh -g -L 3333:localhost:2222 localhost

ssh to lofyer.org:3333 to connect localpc:22

(localpc) ssh lofyer.org -p 3333

Dynamic Forwarding, with -CN to compress data and close terminal input.

To start a SOCKS v4/v5 server on localhost:7777

Then you can use this as a proxy for your browser.

(localpc)$ ssh -CND 7777 [email protected]

Export private key of IIS that cannot be exported

git clone https://github.com/iSECPartners/jailbreak-Windows.git
Run mcc.msc, add Cert, save this MCC as a file(i.e. aaa).
Run jailbreak64.exe mcc.msc aaa
Then you can export the private key from the cert.

iptables route to local pc

iptables -t nat -A PREROUTING -p tcp --dport 5060:5081 -j DNAT --to-destination 192.168.122.222:5060:5081

Change vm root password

virt-sysprep --root-password password:123456 -a os.img

Ubuntu ap-hotspot PPA

sudo add-apt-repository ppa:nilarimogard/webupd8 sudo apt-get update sudo apt-get install ap-hotspot

恢复IO ERROR文件

dd if=ioerror.file of=file bs=1M conv=noerror

QEMU LSI SCSI

qemu-kvm -m 1024 -drive file=centos58-RAW.img,index=0,if=scsi,format=raw -boot c -net nic -net user -nographic -vnc :1 -option-rom 8xx_64.rom,bootindex=1

lsi_bios 下载

yum remove nodeps

rpm -e --nodpes PKG yum install PKG

File too large

ulimit -n 102400 ulimit -f 102400

HTTP REFRESH

AUTORECONF

autoreconf -i

RPi x11vnc auto start and prevent screen from sleeping

pi@raspberrypi:~ $ cat .config/lxsession/LXDE-pi/autostart @lxpanel --profile LXDE-pi @pcmanfm --desktop --profile LXDE-pi @xscreensaver -no-splash x11vnc -auth /home/pi/.Xauthority -display :0 @xset s noblank @xset s off @xset -dpms

Crawl date yesterday

select id,title,content,url,date_format(str_to_date(date, '%d-%M-%Y'), '%Y%m%d') as date_new from posts where date_format(str_to_date(date, '%d-%M-%Y'), '%Y%m%d')=curdate()+0-1;

Simple PHP server

php -S 127.0.0.1:80 -t .

MacOS reinstall

Format U disk at first with 区分大小写，日志式

/Volume/Install\ OSX/Install\ OSX.app/Contents/Resources/createinstallmedia --volume /Volume/install --applicationpath /Volume/Install\ OSX/OSX.app

MySQL select items yesterday

select id,title,content,url,date_format(str_to_date(date, '%d-%M-%Y'), '%Y%m%d') as date_new from posts where date_format(str_to_date(date, '%d-%M-%Y'), '%Y%m%d')=curdate()+0-1;

MACOS all source

macOS 允许所有来源

sudo spctl --master-disable

wp-github all repos limit

120 public function get_repositories() { 121 $contents = $this->get_response('users/' . $this->username . '/repos?per_page=100');

修改iconic右侧widget超链接颜色

.widget-area .widget a { /*color: #757575;*/ text-decoration:none; font-size: 98%; }

CPU IPC usage 4-wide CPU

perf stat -a -- sleep 10

Linux, when adding a new disc

First find your host bus number

grep mpt /sys/class/scsi_host/host?/proc_name

Which should return a line like

/sys/class/scsi_host/host0/proc_name:mptspi

where host0 is the relevant field.

use this to rescan the bus with the following command

echo "- - -" > /sys/class/scsi_host/host0/scan

In the above command the the hyphens represent controller,channel,lun, so – – – indicates all controllers, all channels and all luns should be scanned.

ens/enp rename to eth0

Edit /etc/default/grub At the end of GRUB_CMDLINE_LINUX line append "net.ifnames=0 biosdevname=0" Save the file Type "grub2-mkconfig -o /boot/grub2/grub.cfg" Type "reboot"

Change mysql database or table encoding

SELECT neutron_ml2; ALTER DATABASE neutron_ml2 CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci; ALTER TABLE standardattributes CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

Or if you're still on MySQL 5.5.2 or older which didn't support 4-byte UTF-8, use utf8 instead of utf8mb4:

ALTER DATABASE databasename CHARACTER SET utf8 COLLATE utf8_unicode_ci; ALTER TABLE tablename CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;

Google Pixel 2 network "X" symbol

./adb shell "settings put global captive_portal_https_url https://captive.v2ex.co/generate_204";

title: "transfer IPv6 to IPv4 via socat" date: 2018-10-09 categories: - "linux-admin"

Suppose that you have an ipv6-only server A with ip [ipv6-A], and ipv4-ipv6 server B with ip (ipv4-B, [ipv6-B]).

If you wanna visit http://[ipv6-A]:80, but your ISV does not provide some ipv6 addresses. Now then, you'll make B be your "ipv6-ipv4 relay server" with following guide.

If TCP:

root@B:~# socat tcp4-listen:2222,fork tcp6:[2001:19f0:7001:5a34:5400:01ff:feb5:5bcd]:80

If UDP:

root@B:~# socat udp4-listen:2222,fork udp6:[2001:19f0:7001:5a34:5400:01ff:feb5:5bcd]:80

Now you can visit http://ipv4-B:2222 to access http://[ipv6-A]:80