- Details
- admin
- Redhat / CentOS
yum grouplist
command: yum grouplist
command: /etc/inittab
has become obsolete with Redhat Enterprise Linux version 7. As a result any Linux system using systemd
system management daemon now relies on systemctl
command to change runlevel or to be more precise to change the target. As a result any edits of /etc/inittab
file will not take effect on RHEL 7. The term runlevel
still exists on RHEL 7 and we cat check current runlevel using runlevel
command: [root@rhel7 ~]# runlevel N 3
yum
command and selecting an appropriate installation group. To list all available installation groups on Redhat 7 Linux use: [root@rhel7 ~]# yum group list Loaded plugins: product-id, subscription-manager This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register. There is no installed groups file. Maybe run: yum groups mark convert (see man yum) Available environment groups: Minimal Install Infrastructure Server File and Print Server Basic Web Server Virtualization Host Server with GUI Available Groups: Compatibility Libraries Console Internet Tools Development Tools Graphical Administration Tools Legacy UNIX Compatibility Scientific Support Security Tools Smart Card Support System Administration Tools System Management Done
localhost.localdomain
. This hostname will be shown on various services your new server will offer as well a it will be show on your command prompt such us: [root@localhost ~]#To change your hostname simply edit
vi /etc/hostname
file and inlcude name of your host.Loaded plugins: product-id, subscription-manager This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register. There are no enabled repos. Run "yum repolist all" to see the repos you have. You can enable repos with yum-config-manager --enable
ifconfig
command to display system IP address has become obsolete. Currently, to view an IP address on your RHEL 7 system enter the following linux command: # ip addr show OR # ip a s 2: enp0s3: mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:15:38:b7 brd ff:ff:ff:ff:ff:ff inet 10.1.1.110/8 brd 10.255.255.255 scope global enp0s3 valid_lft forever preferred_lft forever inet6 fe80::a00:27ff:fe15:38b7/64 scope link valid_lft forever preferred_lft forever
systemctl
command is used on RedHat 7 linux to manage services system wide. It allows administrators to manage ssh service to start, restart, stop or enable autoload after system startup. In install ssh service on your RHEL 7 linux run a following linux command: # yum install opensshBy defalt SSH service or to be more precise
sshd
( daemon ) is disabled. Once the opensshd package installed, you can check the status of SSHD service by using the below command: # systemctl status sshd sshd.service - OpenSSH server daemon Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled) Active: inactive (dead)To start ssh daemon (sshd) on RHEL 7 run:
systemctl start sshd
ip
command: # ip addr show 2: enp0s3:mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 08:00:27:15:38:b7 brd ff:ff:ff:ff:ff:ff valid_lft forever preferred_lft forever inet6 fe80::a00:27ff:fe15:38b7/64 scope link valid_lft forever preferred_lft forever
Logrotate is a utility designed for administrators who manage servers producing a high volume of log files to help them save some disk space as well as to avoid a potential risk making a system unresponsive due to the lack of disk space. Normally, a solution to avoid this kind of problem is to setup a separate partition or logical volume for a /var mount point. However, logrotate may also be a viable solution to this problem especially if it is too late to move all logs under different partition. In this article we will talk about usage and configuration of logrotate on RedHat / CentOS Linux server.
Logrotate provides an ability for a system administrator to systematically rotate and archive any log files produced by the system and thus reducing a operating system's disk space requirement. By default logrotate is invoked once a day using a cron scheduler from location /etc/cron.daily/
# ls /etc/cron.daily/
cups logrotate makewhatis.cron mlocate.cron prelink readahead.cron rhsmd tmpwatch
ifcfg
files, that is, defining it as per network interface basis takes a precedence over global system wide default gateway configuration defined by /etc/sysconfig/network
configuration file. routel
command: [root@rhel7 ~]# routel target gateway source proto scope dev tbl 10.0.0.0/ 8 10.1.1.56 kernel link enp0s3 10.0.0.0 broadcast 10.1.1.56 kernel link enp0s3 local 10.1.1.56 local 10.1.1.56 kernel host enp0s3 local 10.255.255.255 broadcast 10.1.1.56 kernel link enp0s3 local 127.0.0.0 broadcast 127.0.0.1 kernel link lo local 127.0.0.0/ 8 local 127.0.0.1 kernel host lo local 127.0.0.1 local 127.0.0.1 kernel host lo local 127.255.255.255 broadcast 127.0.0.1 kernel link lo local
ip=10.1.1.56 - optional netmask=255.0.0.0 - optional vnc - required
Most of the time as a system administrator you are managing your servers over the network. It is very rare that you will need to have a physical access to any of your managed servers. In most cases all you need is to SSH remotely to do your administration tasks. In this article we will configure a GUI alternative to a remote access to your RHEL server, which is VNC. VNC allows you to open a remote GUI session to your server and thus providing you with a full graphical interface accessible from any remote location.
In order to enable an access to our Redhat Linux system using VNC we first need to install it. Make sure that you have your repository enabled and execute the command:
# yum install tigervnc-server