Does yum remove obsolete packages (RHEL) 1

[tumichaelf]

Hello,

When I run "yum update", does this remove the obsolete packages as it upgrades to newer versions?

I ask because the Information Security group at my company has shown that the servers I manage have an older kernel package on them, even though they have been completely upgraded, and according to RHN they are fully up-to-date.

I half-answer my own question with the following command

yum list installed|grep kernel
kernel.x86_64                              2.6.18-238.1.1.el5          installed
kernel.x86_64                              2.6.18-274.el5              installed
kernel-devel.x86_64                        2.6.18-238.1.1.el5          installed
kernel-devel.x86_64                        2.6.18-274.el5              installed
kernel-headers.x86_64                      2.6.18-274.el5              installed

but my question is, is it safe for me to just to uninstall the old kernel's, and how?

Thanks,

Michael

 

[lgarner]

It's normal to install rather than upgrade the kernel since it gives you a failsafe if you can't boot the new kernel.

You can remove old versions with Yum or RPM, just specify the full package name (kernel-2.6.18-238.1.1.el5) instead of just "kernel", and make sure you don't remove the current version (uname -r to check).

Using Yum also gives you that a chance to confirm that you're removing the right one. I'm pretty sure that removing the package also updates the grub.conf, but not 100% so check that also.

 

[tumichaelf]

so in essence you are saying I should do the following

1)

[root@host ~]# yum list installed|grep kernel
kernel.x86_64                              2.6.18-238.1.1.el5          installed
kernel.x86_64                              2.6.18-274.el5              installed
kernel-devel.x86_64                        2.6.18-238.1.1.el5          installed
kernel-devel.x86_64                        2.6.18-274.el5              installed
kernel-headers.x86_64                      2.6.18-238.1.1.el5          installed
kernel-headers.x86_64                      2.6.18-274.el5              installed

2)

[root@host ~]# uname -r
2.6.18-238.1.1.el5

3)

yum remove kernel-2.6.18-274.el5
yum remove kernel-devel.x86_64-2.6.18-274.el5
yum remove kernel-headers.x86_64-2.6.18-274.el5

Is that correct?

 

[tumichaelf]

is there a way to change kernels without rebooting a server?

 

[lgarner]

Not currently. There's been some work done in that area, but frankly I don't see much point and probably won't use the feature if it ever becomes mainstream.

I'd suggest rebooting to the new kernel & removing the old one, rather than removing the new one. -274 is the newest one you have, -238 is the older version.