I recently came across a recommendation from Microsoft regarding the configuration of Logical Volume Management (LVM) in cloud environments, and I find it somewhat puzzling. The recommendation states that while it's possible to configure LVM on any disk attached to a virtual machine (VM), most cloud images won't have LVM configured on the OS disk by default. The reasoning provided is to prevent issues with duplicate volume groups if the OS disk is ever attached to another VM of the same distribution and type, particularly during recovery scenarios. Consequently, the recommendation suggests using LVM only on data disks.
However, I'm struggling to understand the practicality of attaching the OS disk to another VM, especially considering that troubleshooting and diagnostic tasks can easily be performed on separate VM instances. In the event of data recovery, spinning up a new VM without LVM partitions and mounting the LVM volume seems like a straightforward solution.
Furthermore, the argument for using standard partitions over LVM due to their rigidity doesn't seem convincing. LVM offers flexibility in managing disk space, allowing for easier expansion of volumes compared to standard partitions, which can be particularly beneficial if the volume is between other partitions.
I'm curious if anyone can provide insight into scenarios where attaching the OS disk to another VM in a cloud environment would be necessary or advantageous. In my experience, separating system and data disks and attaching data disks to new VMs has been a more practical approach.
I'd appreciate any insights or experiences others might have on this topic.