If you wish to try it, pick a guest or image and do (as root) the following command. You'll have to adjust the drives and mount point(s) suitably, just like with guestfish. # ./fuse/guestmount -a guest.img -m /dev/sda1 --ro --trace -- -f /mnt/tmp Those parameters will produce lots of debugging information and the guestmount command will stay in the foreground so you can see what's going on. Then, also as root, look around the /mnt/tmp directory. read(2) and write(2) aren't implemented (will return EINVAL) so you can't actually read any of the files.

From my limited observations it seems like nothing much is cached. If we added a big "get absolutely everything about this directory" call to the guestfs(3) API and invoked that the first time that FUSE does an lstat(2) (or readdir(2)) call on a directory, that would massively speed up directory listings. There are likely to be lots of opportunities like that.

It's not segfaulted on me yet, but I'm guessing there's a first time for everything ... Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://et.redhat.com/~rjones/virt-top