logical volume management Archive

Hot backup for KVM / libvirt / Xen

Overview We use Xen server on our development server and I decided, it’s time I start making full snapshots of my VM’s. So far we’ve done data backup only, mainly because of storage limitations. Since we got the new server, I have much more disk space now, so I would like to backup whole VM’s.

Tracing I/O usage in Linux

Introduction We know quite few programs that help us identify I/O usage in Linux. In order to identify exactly what is writing and which process, we need to use quite few commands, to make sure we know exactly what is going on. I will show you few useful commands that will help you find your

Restoring deleted/resized logical volume

Calm yourself down Congratulations, you managed to accidentaly remove useful logical volume! No worries! Calm down, it’s all fine, we’ll get it back in few simple steps. Luckily, LVM archives all removed logical volumes when you make lvremove. In order to get it back we can use LVM’s native commands. All we have to do,

LVM Snapshots

What’s purpose of LVM snapshot? Purpose of LVM snapshots is quite simple. We want “point in time” copy of our LV, and snapshot helps us with that, by writing only differences on the snapshot. Why would I do that? It’s ideal for backing up virtual machines or other servers during their operation, since snapshot takes

Creating, extending and shrinking logical volumes (LVM)

In earlier post I explained how to copy logical volumes over network, but I didn’t actually explain how to create LV’s and why exactly use them at all.  Few benefits of using LVM over old partitioning system: Spanning logical volume over many physical volumes, even if they reside on different physical disks (which isn’t really