Linux: some useful command of yum

Yum is a very powful tool in Redhat Linux, it can provide install and update software online.

Some very useful commands

Quiry

1	yum list all

query all softwares in repository

1	yum list installed

softwares already installed on host

1	yum list available

softwares not installed yet, you can install right now

1	yum list updates

show the software that can be updated at once

The following two commands have same function

1 2	yum provides passwd rpm -qf /etc/passwd

Both will tell you what software this command belong to

Yum config documents location

/etc/yum.repo.d/
/etc/yum.conf

About groupinstall

If you want to install a group software, for example,

1 2	yum groupinfo "Scientific Support" Yum groupinstall "Scientific Support"

It will show error

Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirror.fileplanet.com
 * extras: mirror.fileplanet.com
 * updates: mirror.fileplanet.com
base                                                                              | 3.6 kB  00:00:00     
extras                                                                            | 3.4 kB  00:00:00     
ftp.ksu.edu.tw_FTP_CentOS_7_os_x86_64_                                            | 3.6 kB  00:00:00     
updates                                                                           | 3.4 kB  00:00:00     
Warning: Group scientific does not have any packages to install.
Maybe run: yum groups mark install (see man yum)
No packages in any requested group available to install or update

You need to add “group_package_types=default,mandatory,optional” to configuration file.

1	vim /etc/yum.conf

1	group_package_types=default,mandatory,optional

After doing that, you can install the group software successfully.

Add baseurl to your yum repository

1	yum-config-manager --add-repo=http://www.centos.ann

[centos.ann]
name=added from: http://www.centos.ann
baseurl=http://www.centos.ann
enabled=1

It will appear to list /var/cache/yum/x86_64/7

1 2	cd /var/cache/yum/x86_64/7 ll

1	drwxr-xr-x. 4 root root 33 Mar 8 11:13 centos.ann

1	yum repolist

1
2
3

repo id                                 repo name                                                  status
base/7/x86_64                           CentOS-7 - Base                                            10,019
centos.ann                              added from: http://www.centos.ann                               0

It shows centos.ann is the default yum base. 0 means there is no software in it.

Use local disk or CD to yum software

1	vim /etc/yum.repos.d/cdrom.repo

[CDROM]
name=cdrom
baseurl=file:///mnt
enable=1

1	yum --enablerepo=cdrom

In case the rpm verify, you need to add pki

1	rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7