RHEL7: NTP

参考文档

http://www.ntp.org/rfc.html
http://linux.vbird.org/linux_server/0440ntp.php

查看日期时间及NTP概况

[root@rhel7-0 ~]# timedatectl
      Local time: Wed 2014-12-31 12:47:07 EST
  Universal time: Wed 2014-12-31 17:47:07 UTC
        RTC time: Sun 2015-01-04 08:51:13
        Timezone: America/New_York (EST, -0500)
     NTP enabled: n/a
NTP synchronized: no
 RTC in local TZ: no
      DST active: no
 Last DST change: DST ended at
                  Sun 2014-11-02 01:59:59 EDT
                  Sun 2014-11-02 01:00:00 EST
 Next DST change: DST begins (the clock jumps one hour forward) at
                  Sun 2015-03-08 01:59:59 EST
                  Sun 2015-03-08 03:00:00 EDT

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RHEL7: 系统日志(rsyslog, journal)

参考文档

http://fedoraproject.org/wiki/Changes/NoDefaultSyslog
http://0pointer.de/blog/projects/journalctl.html
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/s1-Using_the_Journal.html
https://wiki.archlinux.org/index.php/systemd

rsyslog

rsyslog.conf

日志的优先级。

Code Priority Severity
0 emerg System is unusable.
1 alert Action must be taken immediately.
2 crit Critical condition.
3 err Non-critical error condition.
4 warning Warning condition.
5 notice Normal but significant event.
6 info Informational event.
7 debug Debugging-level message.

继续阅读“RHEL7: 系统日志(rsyslog, journal)”

RHEL7: nmcli网络连接管理

team;

看网卡设备

[root@rhel7-0 network-scripts]# nmcli dev status
DEVICE  TYPE      STATE         CONNECTION 
ens3    ethernet  connected     ens3       
ens6    ethernet  disconnected  --         
ens7    ethernet  disconnected  --         
lo      loopback  unmanaged     --   

[root@rhel7-0 ~]# nmcli device show ens3
GENERAL.DEVICE:                         ens3
GENERAL.TYPE:                           ethernet
GENERAL.HWADDR:                         52:54:00:28:5D:1A
GENERAL.MTU:                            1500
GENERAL.STATE:                          100 (connected)
GENERAL.CONNECTION:                     ens3
GENERAL.CON-PATH:                       /org/freedesktop/NetworkManager/ActiveConnection/1
WIRED-PROPERTIES.CARRIER:               on
IP4.ADDRESS[1]:                         ip = 192.168.122.179/24, gw = 192.168.122.1
IP4.DNS[1]:                             192.168.122.1
IP6.ADDRESS[1]:                         ip = fe80::5054:ff:fe28:5d1a/64, gw = ::

看网络连接的详细信息

[root@rhel7-0 ~]# nmcli con show ens3
connection.id:                          ens3
connection.uuid:                        c078b66a-de02-4165-8026-a7b6f8fe8048
connection.interface-name:              ens3
connection.type:                        802-3-ethernet
connection.autoconnect:                 yes

创建网络连接

[root@rhel7-0 ~]# nmcli connection add con-name ens6 type ethernet ifname ens6 
Connection 'ens6' (3cf83be9-7038-4061-87f9-2f58cf065240) successfully added.
[root@rhel7-0 ~]# 
[root@rhel7-0 ~]# nmcli connection add con-name ens7 type ethernet ifname ens7 
Connection 'ens7' (3e3776e3-fe5f-4f77-8f61-c47428eaf4d6) successfully added.

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Android Studio: 用KVM加速模拟

如果是在Linux上进行开发，可以用KVM来加速Android模拟器。

参考文档

http://developer.android.com/tools/devices/emulator.html#accel-vm

How to Install KVM and Create Virtual Machines on Ubuntu

测试环境

Ubuntu 14.04
Android Studio 1.0

配置过程

1. 安装KVM

$ sudo apt-get install qemu-kvm libvirt-bin ubuntu-vm-builder bridge-utils

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