Different list of installed packages reported by rpm compared to yum

yum list installed has 930 lines while rpm -qa has 895 lines, what might be the difference ?

This is likely just formatting differences. yum list will do a bunch of clever wrapping to your terminal size.

What you probably want to do is use:

# Run this on the master server
yum-debug-dump

# Run this on the new server, with the input from the above.
yum-debug-restore

what might be the difference ?

The primary reason for the differing number of lines is that the output produced by yum is formatted so that each field lines up vertically (regardless of the length of the package name and/or version number). It does this by using two lines for listing such packages and padding the second line with space characters to line up the fields correctly. The following output (from a CentOS 6 box) shows that two lines are used to list the device-mapper-persistent-data.x86_64 package:

device-mapper-libs.x86_64         1.02.95-3.el6_7.4    @clearos-verified-updates
device-mapper-persistent-data.x86_64
                                  0.3.2-1.el6          @clearos
dhclient.x86_64                   12:4.1.1-49.P1.v6    @clearos-verified-updates

However, this is not the only reason and it can be seen by massaging the output of the two commands before comparing them:

For the output of rpm command:

  1. Sort it so that packages beginning with an upper case letter appear before those with lower case:

    rpm -qa | LC_ALL=C sort

  2. Use a sed command to remove the package version numbers:

    rpm -qa | LC_ALL=C sort r | sed 's/-[^-]*-[^-]*$//' >| installed.rpm

For the output of the yum command:

  1. Remove the first two header lines (Loaded plugins and Installed Packages):

    Loaded plugins: etckeeper, fastestmirror
Installed Packages

    We can use sed for this:

     yum list installed | sed '1,2d;'

  2. We can also use sed to remove all the lines that are continuations of a package listing (these lines begin with a number of spaces so that all the package versions line up).

    yum list installed | sed '1,2d;/^ /d;s/\..*//' >| installed.yum

Now, we can use the diff command to compare the output of the two files. Here’s the results from the CentOS 6 box:

# diff installed.{rpm,yum}
239,243d238
< gpg-pubkey
< gpg-pubkey
< gpg-pubkey
< gpg-pubkey
< gpg-pubkey

Conclusion

This shows that rpm -qa also includes package listings for the public keys that are trusted to sign packages while the yum command omits these packages.

Tags:

Rpm

Yum

Centos

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