RHEL and CentOS study notes

RHEL and CentOS Study Notes 1. disable firewall (1) serviceiptablesstop this is directly disabled (2)/etc/init. d/iptablestop: The effect is the same as that of the First Command (3) chkconfigiptablesoff, which is permanently disabled...
RHEL and CentOS Study Notes 1. disable firewall (1) service iptables stop (2)/etc/init. d/iptable stop: the effect is the same as that of the First Command (3) chkconfig iptables off, which is permanently disabled. 2. exception: Another app is currently holding the yum lock; waiting for it to exit... when using yum to upgrade some files, the following situations may occur: another app is currently holding the yum lock; waiting for it to exit ...; you can forcibly turn off the yum process: # rm-f/var/run/yum. pid and then you can use yum. Www.2cto.com 3. Red Hat Enterprise 6 modify the host name (1) run the command to temporarily modify the host name hostname # view the host name of the current host hostname MASTER # temporarily modify the current host name-the host name becomes invalid after restart. (2) run the command to modify the host name hostname # view the host name of the current host and modify the network file # vi/etc/sysconfig/network NETWORKING = yes HOSTNAME = MASTER (: wq save and quit)
(3) modify the hosts file vi/etc/hosts 127.0.0.1 localhost. localdomain localhost www.2cto.com # vi/etc/hosts 127.0.0.1 localhost. localdomain localhost4 localhost4.localdomain4 // This row is strongly recommended to retain: 1 localhost. localdomain localhost6 localhost6.localdomain6 // This row is strongly recommended to retain #192.168.0.1 rhel.lpwr.net rhel // there must be three fields: IP, FQDN, HOSTNAME 127.0.0.1 MASTER. localhost MASTER 192.168.80.10 MASTER. localhost MASTER (4) restart # shutdown-r now # reboot 4. NTP configuration (1) check if the NTP service is installed: rpm-qa | grep ntp (2) in the file ntp. add the following in the conf file: restrict 192.168.80.0 mask 255.255.0 nomodify notrap # Open to 192.168.80 CIDR block and cannot be modified. add multiple entries as needed (3) run ntp service ntpd start (4) check whether ntp is working ntpq-p (5). set ntp service to start chkconfig ntpd on www.2cto.com 5. configure the local ISO file as the YUM source (1) create a folder and create a folder/rhrliso under/mnt/. Copy the left and right files in the ISO file to the rheliso folder. (2) create a local file. repo in/etc/yum. repos. d. repo, file content: [local-Server] name = RHEL 6.3 ISO REpo baseurl = file:///mnt/rheliso/ Enabled = 1 gpgcheck = 0 (3) run the YUM command yum clean all yum list