On Tue, Nov 17, 2015 at 06:08:49PM -0600, Richard Owlett wrote: > In some of my reading I came across a page recommending LVM for ease > of adjusting space. > > When searching for more information all I'm finding are essentially > HOWTO's with only a couple of paragraphs on "Whats" and "Whys". > Essentially nothing on "Why not". > > No information on dual boot. > > Suggestions?
Here's why not: LVM is a kludge. That doesn't mean it isn't useful, but it does mean that it's rarely the best tool. LVM can increase the size of partitions by giving them more space on either an empty section of disk or another disk. Either way, you then need to increase the filesystem size on that partition, which is usually but not always doable. It does not grant any extra redundancy, so when you add an extra disk, you have increased your chances of hardware failure taking out data. LVM can snapshot a partition, so that you can back it up or go back in time. Doing so is more complex, hairy, and time-consuming in LVM than in most alternatives, and should usually be avoided. LVM can do RAID mirroring, but not as well as mdadm RAID1 or 10. LVM can do RAID striping, but not as well as mdadm RAID0 or 10. LVM can do RAID5 or 6, but it takes more thought than with mdadm, and most people should avoid RAID5 or 6 most of the time. If you need to move things around once in a while, having a nice big disk available to use as a spare and copying things with rsync and dd is going to be easier. If you need to move things around a lot, you might want btrfs or zfs instead of lvm. If you don't need to move things around much, but just want performance, mdadm is better. -dsr-
