Fedora checks all repository for updating when every time i want to install some packages from yum. this is waste of time because i know they are updated!
how could i disable this checking?
if you know yum is updated then before going to install go to
/etc/yum.repos.d directory and edit /etc/yum.repos.d/fedora-updates.repo
and make changes in updates. In updates there is a value enabled set to 1, so change this to 0.
…where value is one of: 0 — Do not include this repository as a package source when performing updates and installs. This is an easy way of quickly turning repositories on and off, which is useful when you desire a single package from a repository that you do not want to enable for updates or installs. 1 — Include this repository as a package source. Turning repositories on and off can also be performed by passing either the --enablerepo=repo_name or --disablerepo=repo_name option to yum, or through the Add/Remove Software window of the PackageKit utility.
You can Simply use :
yum --disablerepo=\* --enablerepo=your_repo install packagename
You can list repo using :
if you want to disable permanent then you have to edit
/etc/yum.repos.d/*.repo and disable it manually
The "repo is up to date" check is fast, so it shouldn't be a bother. Going around disabling repositories for the sake of a few seconds will exact bloody revenge later...
If you are worried that
yum -y install package-A; yum -y install packge-B; ... will do checking over and over, just do
yum -y install package-A package-B ...
BTW, Fedora 18 has the experimental
dnf yum replacement, much faster and accurate. It can be installed in paralell. Works like a charm, but still has some rough edges (when it decides that there are unresolvable conflicts, it just finishes silently without doing anything).