too many mounted file systems

I´m not sure this is a security issue. I have reached the NFS mount limit of 256 mounts on my machhine. I did not know before there was one... How do I extend that to get 100% connect from my backup machine? The Message while mounting mount 257 was: mount: wrong fs type, bad option, bad superblock on localhost:/usr/home/vserver/lib, or too many mounted file systems Background: I use NFS (localhost -> localhost) to get a lot of users their own virtual server in a chrooted box, but using some of shared directories, so every chrooted box uses multiple mounts. Thx, Bernhard