Anyway to re-size root partition without using live CD ?
 

Any one ever use VPS web hosting ?
I'm going to order an OpenVZ VPS hosting, and I think the hosting company will give me a linux with one big root partition only.
Since it is a VPS, I can't use a live CD to re-partition.
Is there anyway to re-size root partition without using live CD ?

Would be helpful to know which distribution and version is running.

Let's say Debian 7 64 bit.

Is it worth risking your system ?. i.e., why do you care ?.

Short answer - the old school way still works, even for the root (for ext[34]). Shrink the filesystem, delete the partition (fdisk say), re-define the partition, good to go.
Don't cock it up - especially aligning the filesystem and the start of the (re-defined) partition. If you're lucky you'll know you got it wrong immediately, else maybe on the next re-boot.
Of course if they insist on XFS you're out of luck anyway.

Have you tried asking the provider about custom partitioning schemes?

Just got the reply from the provider. Only XEN and KVM allow user to modify the partition. OpenVZ can't.
Seems that they provide a panel to do that.

That makes sense, since, AFAIK, OpenVZ is a container format, not a VM (which also explains why they don't offer to boot from a live-CD).