Question

28

How can I create one logical volume over two disks using LVM?

rated 0 times [ 28] [ 0] / answers: 1 / hits: 91643 / 3 Years ago, tue, october 5, 2021, 3:44:30

Hi. I've got a working Ubuntu 12.04 server, which is going to serve as media server. I've added two disks of size 3TB to put my data on, and I wish to combine these as one 6TB logical volume which I could mount under /media.

So far, I have created one partition on each disks with fdisk and formatted them to ext3. But now I am stuck on how to continue. Do I use Mdadm to create a Jbod array? Or do I use LVM to make a logical volume of these two disks? I can't seem to find the documentation I need, it's mostly about extending existing volumes or installing a fresh system which I don't need.

My OS is on /dev/sdc1 (it's a USB thumb-drive), and the two newly created partitions are on /dev/sda1 and /dev/sdb1.

Hope you can give me some directions.

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

dresuitable

Add To Favorites

Follow

Total Points: 69

Total Questions: 116

Total Answers: 122

Location: Honduras

Member since Sun, Dec 26, 2021

2 Years ago

answered 3 Years ago tresein · Accepted Answer

You should have a look at this detailed answer.

Here's a summary of it:

Create a physical volume on the first hard drive, and another physical volume on the second hard drive.

Create a new volume group, assigning both physical volumes to it.

Create a new logical volume in that volume group.

Create a new ext3 filesystem in that logical volume.

The diagram I copied from this answer visualises this (but with three filesystems, rather than just one):

LVM schema

As you can see, creating an ext3 filesystem is the last step, not the first. If you have an existing ext3 partition that isn't in LVM, you can't migrate it to LVM. You'll have to backup the partition, delete the partition, setup LVM, and then copy the files back.