Centos Notes

自动启动网卡 CENTOS安装完后,网卡默认没有激活,无法分配IP地址 /etc/sysconfig/network-scripts/ifcfg-enp0s3 DEVICE=enp0s3 BOOTPROTO=dhcp ONBOOT=yes systemctl restart network set the default route on interface DEFROUTE="yes" 删除MariaDB rpm -qa | grep mariadb sudo yum remove -y mariadb mariadb-server rpm -qa | grep mariadb yum remove -y mariadb-libs-5.5.65-1.el7.x86_64 rm -rf /var/log/mariadb rm -f /var/log/mariadb/mariadb.log.rpmsave rm -rf /var/lib/mysql rm -rf /usr/lib64/mysql rm -rf /usr/share/mysql install sudo yum install MariaDB-server sudo systemctl start mariadb.service 安装polipo git clone https://github.


之前一直用pycharm,今天把code升级到1.3.2的时候, 突然提示我安装python扩展,决定试试。 结果发现python的解释器设置有问题, 总是设置为系统的解释器, 而虚拟环境的解释器不起作用。 apt remove --purge python3.5 reboot 结果ubuntu桌面启动不了。好多应用程序例如chrome,virtualbox都消失了, 造成了很大的麻烦。 Ctrl+Alt+F1进入虚拟控制台登录 apt install python3.5 apt install ubuntu-desktop 重新安装chrome和virtualbox cd /etc/apt/sources.list.d sudo mv google-chrome.list apt update apt install google-chrome-stable

Vxlan on Linux

端到端VXLAN(unicast) ip a ip link add vxlan0 type vxlan \ id 42 \ dstport 4789 \ remote \ local \ dev eth0 ip -d link show dev vxlan0 ip addr add dev vxlan0 ip link set vxlan0 up ip r default via dev eth0 dev eth0 proto kernel scope link src dev vxlan0 proto kernel scope link src bridge fdb | grep vxlan0 ip neigh 多播vxlan(multicast)

Linux performance

putting /tmp on tmpfs Interrupt Coalescence ubuntu 16 default Interrupt Coalescence (IC) $ethtool -c enp0s25 Coalesce parameters for enp0s25: Adaptive RX: off TX: off Pause frames $ethtool -a enp0s25 Pause parameters for enp0s25: Autonegotiate: on RX: on TX: on network Tuning the network adapter (NIC) use Jumbo frames ifconfig eth0 mtu 9000 ip result for a healthy system with no packet drops ip -s link show eth0 stop irqbalance for home user


常用命令 常用命令 bandwidth utilization tool wget -qO-${WHAT_VERSION}/bandwhich-v${WHAT_VERSION}-x86_64-unknown-linux-musl.tar.gz | tar xvz -C ~/bin/ bandwhich TCP tcpdump-windows TCP DUMP

Linux Chrome

禁止启动时候恢复页面提示 Version 73.0.3683.86 (Official Build) (64-bit) 方法1(可靠) 首先关闭chrome,然后修改下面的设置,修改完后重启 .config/google-chrome/Default/Preferences sed -i '/exit_type:Crashed/exit_type:Normal/` windows用户请参考下面的视频 Chrome Didn’t Shut Down Correctly Error Solved Windows 7 方法2(不可靠) Type in address bar (Crtl+L). chrome://flags/#infinite-session-restore Click on the right drop-down menu and change the ‘Default’ value to ‘Disable’. Then restart Chrome to apply that setting enter password to unlock your keyring 方法1(可靠) set password-store to basic dpkg -L google-chrome-stable |grep desktop | xargs cp {1} ~/.


标准设备 Bridge: A Linux bridge behaves like a network switch. It forwards packets between interfaces that are connected to it. It’s usually used for forwarding packets on routers, on gateways, or between VMs and network namespaces on a host. It also supports STP, VLAN filter, and multicast snooping. TUN: TUN (network Tunnel) devices work at the IP level or layer three level of the network stack and are usually point-to-point connections.

Linux SSH

ssh client config ~/.ssh/config host * StrictHostKeyChecking no Enables forwarding of the authentication agent connection client config .ssh/config ForwardAgent yes Enable ssh-agent on main device .bashrc SSH_ENV="$HOME/.ssh/environment" function start_agent { echo "Initialising new SSH agent..." /usr/bin/ssh-agent | sed 's/^echo/#echo/' > "${SSH_ENV}" echo succeeded chmod 600 "${SSH_ENV}" . "${SSH_ENV}" > /dev/null /usr/bin/ssh-add; } # Source SSH settings, if applicable if [ -f "${SSH_ENV}" ]; then .


tl;dr uget sudo mount -t tmpfs tmpfs /takeover/ sudo mount -o loop,ro -t iso9660 ~/systemrescuecd-6.0.2.iso /mnt/cd cp -rf /mnt/cd/* /takeover/ curl -L > busybox chmod u+x /takeover/busybox git clone gcc -o ./fakeinit

Ubungu Chinese locale

/etc/default/locale update-locale LANG=zh_CN.UTF-8 # File generated by update-locale LANG="en_US.UTF-8" LC_NUMERIC="zh_CN.UTF-8" LC_TIME="zh_CN.UTF-8" LC_MONETARY="zh_CN.UTF-8" LC_PAPER="zh_CN.UTF-8" LC_NAME="zh_CN.UTF-8" LC_ADDRESS="zh_CN.UTF-8" LC_TELEPHONE="zh_CN.UTF-8" LC_MEASUREMENT="zh_CN.UTF-8" LC_IDENTIFICATION="zh_CN.UTF-8" LANGUAGE="zh_CN:en_US:en"

linux note

iptables规则配置 表与链 调用链顺序 检查内存 ram speed and type dmidecode sudo dmidecode --type memory # dmidecode 3.0 Getting SMBIOS data from sysfs. SMBIOS 2.6 present. Handle 0x003E, DMI type 17, 28 bytes Memory Device Array Handle: 0x003C Error Information Handle: Not Provided Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: 1 Locator: XMM1 Bank Locator: Not Specified Type: DDR3 Type Detail: Synchronous Speed: Unknown Manufacturer: JEDEC ID: Serial Number: Asset Tag: Not Specified Part Number: Rank: Unknown lshw

Linux File System Read Write Performance Test

dstat $dstat -d -nt $dstat -nt $dstat -N eth2,eth3 pkstat sudo apt-get install pktstat sudo pktstat -i eth0 -nt nethogs sudo apt-get install nethogs sudo nethogs EPEL $ cd /tmp $ wget # rpm -ivh epel-release-6-8.noarch.rpm How do I use EPEL repo? Simply use the yum commands to search or install packages from EPEL repo: # yum search nethogs # yum update # yum --disablerepo="*" --enablerepo="epel" install nethogs System administrators responsible for handling Linux servers get confused at times when they are told to benchmark a file system’s performance.

shell script

push docker images to ali registry-mirrors #!/usr/bin/env bash docker login --username=wubigo docker images | grep v1.13 | awk '{ print $1 }' | sed --expression=s'/\///' | xargs -i -t docker tag{}:v1.13.3{}:v1.13.3 docker images |grep ""| awk '{ print $1 }'| sed --expression=s'/\/co1\///' | xargs -i -t docker push{}:v1.13.3 docker push through cache #!/usr/bin/env bash if [ -z "$VM" ]; then VM = t1 echo "VAR VM is not set" exit fi tee daemon.