Does anyone turn quotas on when setting up a VPS? There are problems in Plesk if they aren't turned on because you can't allocate space for web users. I haven't turned mine on because I'm uncertain of the risks with that if there are any.

What Virtualisation technology are you using ?
XenServer works fine with quota's enabled

I'm using Virtuozzo

So not virtualisation at all, just "timeslicing" - no idea about how it manages quota's if at all - why not ask Parallels ?

Are you referring to turning on and off the quotas per container? Shouldn't that normally be ON so you're not allowing someone to overuse the node/container that you had setup?

The upstream provider mentioned that they don't turn on quotas in the container. I don't know the reason for it. Plesk and cPanel still manages space but it's not done through the server configuration. The problem with this is that space in subdomains and user accounts cannot be limited.

Why not, you can manage quotas to have one more space manager except CP

We do use OpenVZ , Xen , HVM and Hyper -V , however we have found Xen more effective and smooth to work with.

We do use OpenVZ , Xen , HVM and Hyper -V , however we have found Xen more effective and smooth to work with.We have been providing Virtuzzo too , however we have discontinued them for such issues earlier.

Xen is really good.
It is nice to work with it.