Jail to jail network performance?

[Brandon Fosdick]

Robert Watson wrote:
 > (1) Modifying the name space exclusion assumption for jails, so that the
>     file system name spaces overlap.  One way to do this is with nullfs.

nullfs looks interesting. I was thinking about sharing files between jails using NFS, but it looks like nullfs would do the trick with better performance. Although the bugs section of the man page for mount_nullfs is rather scary. Does anyone have any experience with it? Does it actually work?

If the point here is to make /tmp/mysql.sock show up in another jail's file space, can I use a symlink instead? Can a jailed process see the target of the symlink?