yum or rpm

Hi Srikanth,

To answer your initial question, if possible, use yum, that's the short answer. There are cases where you can use rpm....

NOTE: Also see the good tips from Jaromir Hradilek and Tom Jones below....

If you have not already, activate your Red Hat subscription, and you can activate it at this link https://access.redhat.com/subscriptions/activate/protected/activate.html?_flowId=activate-flow&_flowExecutionKey=e1s1.
The activation of your subscription should enable your yum repository from Red Hat (if you have not already done so). run a "yum clean all" and "yum repolist" after activating your subscription.

First of all, both rpm and yum have their place. rpm does not resolve software dependencies, yum does if it points to a proper yum repository for your system. Using the rpm command can land you into a not-wonderful place called "rpm dependency hell". For some info on "rpm dependency hell", see slide 8 of this Red Hat bit on package management TAKES A MOMENT TO LOAD, and the remaining slides at your convenience.

Using yum for install and removal helps with the dependency issues. When you go to uninstall software, yum will resolve dependencies as well. If possible, use yum to add and remove software to avoid 'dependency hell' (see slide 8 of the link in the last paragraph). There are exceptions of course, if you have a single or a couple of rpms with zero dependencies,

Some background for rpm
- Here is a good reference for rpm called "maximum rpm" website

Testing an rpm for install/removal without actually installing or removing it

• Test the install with "--test" (link further in this post):

rpm -ivh --test name_of_the_rpm

• Test the removal with "--test" (link further in this post):
  -- NOTE: use the "--test" to test, omitting it will erase the rpm.

rpm -e --test name_of_the_rpm
[no output means it would run clean]

• or

rpm -evv --test name_of_the_rpm
[longer verbose output]

After determining the rpm has no dependencies, here is how to install it with the rpm command:
- you can use

rpm -ivh /path/to/the.rpm

Or if you had two rpms to install together:

rpm -ivh /path/to/the.rpm   /another/path/to/another.rpm

Here is one way to test the removal of an rpm using yum, without actually executing the actual removal as follows:
-- and hit "n" when prompted (you can use the below to test an install, but switch "remove" with "install").

yum remove nameofthe_rpm
[output not listed here]
Is this ok [y/N]: n
Exiting on user Command

Alternatively, (I've never seen this documented), but this also does the same as above, but exits immediately:

echo n | yum remove nameofthe_rpm

Additional background

Yum and 3rd party software
- I've had to occasionally load software provided by third party vendors on my Red Hat systems that is in rpm format. I will often still use the following, because some software packages will still ask for additional libraries etc, and yum will attempt to resolve dependencies.

yum install /path/to/the_3rd_party_vendor.rpm

• This may seem obvious, but I've seen it happen to another company - If you are dealing with unique channels or are creating your own yum repositories, only apply a workstation yum repository to a workstation, and server yum repository to RHEL server. Mixing those ends with bad consequences, and I know of a company that mixed these up and suffered some bad consequences. Get the versions right as well.

• Some very brief background on the yum command

• Here is a video on basic yum use by Red Hat.

Hope this helps.