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View Full Version : [ubuntu] LVM or EXT4?



fullmoonguru
December 6th, 2012, 01:03 AM
A while ago I was looking at changing teh size of a partition on a 2 TB drive I had on a home server/HTPC. It was going to take days, or did take days, or something I can't remember. But I do remember learning about LVM & how it was better for managing large disk spaces.

OK, so I'm rebuilding this PC only now I have a 120GB SSD drive for my normal partitions and the 2 TB drive just for data. With the large drive just one big data partitions, does LVM do anything for me? If I ever need more space, I don't see adding drives. I'll just swap out for a 4 TB drive or something.

darkod
December 6th, 2012, 01:08 AM
LVM is useful for combining more physical disks into one logical space. That means if you set up LVM on the 2TB disk right now, when adding another 2TB for example tomorrow, the available capacity can grow to 4TB without any data moving/copying.

On the other hand, if you would rather swap the disk with a larger one when it's full, you don't need LVM at all. However, you will need to wait for 2TB of data to finish copying when doing the switch.

Another important LVM benefit, is that "partitions" in the LVM are called Logical Volumes, and you can dynamically change their size. However, on a data disk if you are happy having one big partition, it offers no benefit for you.

fullmoonguru
December 6th, 2012, 01:44 AM
Great, thanks for the quick reply

jerome1232
December 6th, 2012, 01:51 AM
Another benefit of LVM is snapshots, you can make a snapshot of a volume which basically freezes it in time, and then make a backup of the snapshot.

That way you avoid backing things up and having them change on you during the backup causing inconsistencies.

oldfred
December 6th, 2012, 01:55 AM
Unless changing partitions around a lot LVM may not offer much.

Advantages/Disadvantages LVM Post #9
http://ubuntuforums.org/showthread.php?t=1586328
lvm info older:
http://ubuntuforums.org/showthread.php?t=141900
http://tldp.org/HOWTO/LVM-HOWTO/index.html