I am trying to get an nfs client running on a Sheeva-plug running debian 2.6.22. The host is Ubuntu 12.04 and claims (from showmount -e) to be exporting the desired directory. There is no showmount binary in the sheeva-plug, so I'm trying to install it from the nfs-common package: # apt-get install nfs-common The response ends with E: could not open lock file /var/cache/apt/archives/lock - open (no such file or directory) E: Unable to lock the download directory. I am root while doing this. Similar errors arise when trying to install other packages. How do I correct these errors so apt-get will do its work?