Converting Ext3 to LVM

Basic steps. This will need a cleanup (and is only relevant for RHEL/Fedora at the moment)

LVM (Logical Volume Manager) is a layer that sits between physical volumes and your filesystems. It's a bit like partitioning on steroids, but the key is that it's dynamically variable. Windows users will find it similar to the Dynamic Disk functionality (but much cooler).

LVM allows you to pool physical resources together (typically hard drives) into a Volume Group, and then carve out chunks into Logical Volumes. You then format these with a filesystem as you would normally do to an on-disk partition. LVM also gives you the ability to resize your logical volumes (provided you haven't used all the space in your volume group). With modern filesystem tools, this can even be done with zero downtime!

This procedure assumes you've got an existing system with a bunch of partitions that you'd like to convert to LVM. Most of our systems use md-based RAID arrays as the block device for each filesystem, which features in this procedure. You may need to adjust the procedure accordingly.

The GRUB bootloader can't boot directly to an LVM system. This means your kernel and initrd (if required) will need their own partition for /boot. After this, the rest of the drive is given over to LVM.

Wiki: dedicated/Convert_Ext3_to_LVM (last edited 2008-09-26 12:00:44 by AndrewRogers)