Problems with core and plugin updates (Slow)

Hi,

I run a VPS and there are multiple accounts with WP installed. They’re all experiencing the same thing. When updating core or plugins, they take forever.

Essentially, I can click on update/upgrade, then fill in the FTP details (It asks for them every time) and wait. It takes forever… And sometimes works, but sometimes it yields a “Could not copy file” error.

In the interest of experimentation, I CHMOD’d -everything- to 777, that got me nowhere. So I’m stuck.

Anyone know what I tweak in WHM to make my (and the lives of everyone else on my VPS) easier? And maybe what directories/files should be CHMOD’d to what?

Thanks.