I have a setup of about 20 Linux machines, each with about 30-150 gigabytes of customer data. Probably the size of data will grow significantly faster on some machines than others. These are virtual machines on a VMware vSphere cluster. The disk images are stored on a SAN system.

I'm trying to find a solution that would use disk space sparingly, while still allowing for easy growing of individual machines.

In theory, I would just create big disks for each machine and use thin provisioning. Each disk would grow as needed. However, it seems that a 500 GB ext3 filesystem with only 50 GB of data and quite a low number of writes still easily grows the disk image to eg. 250 GB over time. Or maybe I'm doing something wrong here? (I was surprised how little I found on the subject with Google. BTW, there's even no thin-provisioning tag on serverfault.com.)

Currently I'm planning to create big, thin-provisioned disks - but with a small LVM volume on them. For example: a 100 GB volume on a 500 GB disk. That way I could more easily grow the LVM volume and the filesystem size as needed, even online.

Now for the actual question:

Are there better ways to do this? (that is, to grow data size as needed without downtime.)

Possible solutions include:

• Using a thin-provisioning friendly filesystem that tries to occupy the same spots over and over again, thus not growing the image size.

• Finding an easy method of reclaiming free space on the partition (re-thinning?)

• Something else?

A bonus question: If I go with my current plan, would you recommend creating partitions on the disks (pvcreate /dev/sdX1 vs pvcreate /dev/sdX)? I think it's against conventions to use raw disks without partitions, but it would make it a bit easier to grow the disks, if that is ever needed. This is all just a matter of taste, right?