RHCK and vdo/kmod-vdo dependency

Microlinux

Hi,

I'm currently in the process of gradually moving all my servers from CentOS 7 to Oracle Linux 7. So far I migrated half a dozen machines, and by now the process is trivial for me.

One of my servers has a relatively small /boot partition. After migrating it, I noticed I got an Icinga alert about a full partition. Indeed, /boot was 93% full. Which was due to the fact that I had two upstream Red Hat kernels as well as two Oracle kernels.

I read the documentation on how to remove the Red Hat kernels and decided to give it a go. I installed the kernel-transition package and removed the kernel, kernel-tools and kernel-tools-libs packages. Which freed my /boot partition as expected.

I noticed while removing the kernel packages that two other packages went down the drain with them, namely vdo and kmod-vdo. I don't know what they are good for. I know they belong to the "Base" package group.

Should I be worried about some important stuff missing ?

Cheers,

Niki

Avi Miller-Oracle

If you're ever wondering what a package does, yum info packagename will tell you. In this case, the vdo package contains the management tools for the Virtual Data Optimizer and the kmod-kvdo package contains the kernel modules for the Virtual Data Optimizer, which is (according to its description) a device mapper target thatdelivers block-level deduplication, compression and thin provisioning.

Microlinux

I read that description which still leaves me a bit clueless.

• I don't know exactly what it's supposed to do.
• I don't think I need it.
• Since it's part of the "Base" package group, I still wonder if it is something vital under the hood.

Avi Miller-Oracle

Sorry, I guess I should provide more context:

Device-mapper targets like dm-raid or dm-multipath sit on top of phsyical block devices to provide additional functionality. For example, dm-raid creates a RAID device, while dm-multipath allows for multiple connections to the same device. VDO creates a virtual device that does things like block deduplication and compression.

If you haven't configured it, you don't need it. It's not configured by default and requires manual intervention.

There are lots of things in the Base package group that are never used. You can always reinstall it if you want to take it for a spin.

Microlinux

Strangely, these are the only two packages that seem to have a hard dependency on RHCK and don't work with only UEK installed.