Linux+ Logical Volume Management (LVM) Flashcards

An LVM snapshot is running out of space. What happens when a snapshot COW space is 100% full?

Answer: The snapshot becomes invalid and is automatically deactivated

When a snapshot's copy-on-write space is exhausted, the snapshot is marked invalid and deactivated, making it unusable.

Which command removes a physical volume label, making it a plain block device again?

Answer: pvremove /dev/sdb

pvremove destroys the LVM metadata on a physical volume, returning it to an uninitialized state.

What does the 'vgchange -a y vg0' command do?

Answer: Activates all logical volumes in vg0

vgchange -a y (--activate y) makes all logical volumes in the specified VG available as block devices.

Which LVM command is equivalent to running pvcreate + vgcreate + lvcreate in sequence for a simple setup?

Answer: There is no single command; each step is always separate

LVM requires separate pvcreate, vgcreate, and lvcreate commands; no single command performs all three steps.

A striped LV was created across 3 PVs. One PV fails. What is the result?

Answer: The entire logical volume becomes inaccessible due to data loss

LVM striping has no redundancy (like RAID 0), so a single PV failure causes the entire LV to become inaccessible.

Which file contains the default LVM configuration settings on a Linux system?

Answer: /etc/lvm/lvm.conf

The main LVM configuration file is /etc/lvm/lvm.conf, which controls filters, cache settings, and other LVM behaviors.

What is the purpose of 'lvmetad' in LVM?

Answer: A metadata caching daemon that speeds up LVM operations by caching PV/VG metadata

lvmetad caches LVM metadata in memory so that tools like vgscan don't need to scan all block devices on every invocation.