Ingo Weinhold wrote: [...] >> having dozens of mounts, > > Mounting packages individually and joining them via a union FS would likely > be a problem, but I believe Jonas was thinking of only a single mounted FS > making available the contents of all installed packages. Reading back, I don't know where I got the impression that he meant union mounting each package directly. He clearly said that pkgfs would monitor some folder for packages and present those as one file system. I guess a pkgfs should behave like a read-only ram disk, except that it occasionally changes its content to mirror the monitored folder. If you want to union mount it, this should be orthogonal to the implementation of pkgfs itself - any FS can overlay any other. The work done on mount could be reduced by dumping memory to a file on umount. When remounting, pkgfs would need to check that the monitored folder has not changed. If it has, it is probably best to just ignore the cache file.