Docs: Add LVM activation and EFI mount steps to RHEL/CentOS VM import guide

[sethesterline]

Summary

The RHEL/CentOS Linux VM import guide is missing two critical steps for LVM-based and EFI systems, causing mount -a to fail during the chroot process.

Type

How-to Guide (update to existing article)

Article: https://docs.verge.io/knowledge-base/import-rhel-centos-vm/
Source file: docs/knowledge-base/posts/import-centos-redhat.md

Problem

In Step 3 (Mount the Root Filesystem and Chroot), the guide instructs users to run mount -a after chrooting. On LVM-based systems, this fails because LVM volume groups are not automatically activated in rescue mode — the logical volumes simply aren't visible yet.

Additionally, on EFI/UEFI systems, the EFI partition is not mounted before chrooting, so the dracut rebuild does not update the EFI boot entries.

Suggested Changes

Before Step 2 (Mount the root partition), add:

If your system uses LVM, activate volume groups first:

vgchange -ay

Then verify logical volumes are visible with lvdisplay before proceeding.

Between Step 4 (Bind virtual filesystems) and Step 5 (Chroot), add:

For EFI/UEFI systems, also mount the EFI partition:

mount /dev/sdX1 /mnt/boot/efi

Replace /dev/sdX1 with your actual EFI partition (check with lsblk or fdisk -l).

Context

Requested via support interaction. Surfaced from case 00012019 — customer running RHEL 9 with LVM groups on an airgapped VergeOS tenant. The dracut steps from the current guide failed specifically because mount -a could not resolve LVM mounts in rescue mode.