"RAID stands for "Redundant Array of Inexpensive Disks."
Acually "RAID stands for " Redundant Array of Independent
But is aften called Inexpensive.
What is the relation between LVM and RAID?
LVM and Raid are two totaly different things, Raid is for disk managment and LVM allows you to manage partitions.
Logical Volume Management = LVM
= Physical Volume
...This would be the hard drive, a physical volume can not span multiple hard drives. if you have more than one hard drive you will have more than one Physical Volume.
= Logical Volume Group
...The LVG can consist of more than one Physical Volume so if you have multiple drives, lets say two, your LVG will or could be setup using both drives or only one if you so choose.
= Logical Volume
The Logical Volume Group
is divided into Logical Volumes these are simalar to partitions but a little different. Each LV will be like a partition as in one will be for / one for /home swap and so on. And free space so that you can grow a LV if needed.
Can I create LVM without RAID?
What is the recommended size?
That will depend on how much you would like to give each OS.
10gb is more than enough for most Linux Distro's with a partition set aside for storage or to share between OS's.
Lets say you have one hard drive of 100GB
/boot = 100mb classic primary partition, this will be your boot partition, it is NOT
part of the LVG. If you plan on having more than two distro's you may want to make this a little bigger.
LVG = Take all the remaining space for this.
LV = This is ware you will divide the LVG into partitions for /, /home, swap, make sure you leave free space for growth.
Lets say for install Fedora.
/ = 20GB for Fedora
20GB for future distro.
swap = 512mb
maybe 30GB to share file between OS's
The rest free space for growth.