Motorola has 4 HA pairs running in Swindon, UK. Three clusters serve an SMB front for NFS mounted data on EMC Celerras: PII 233MHz, 3GB HD, 96MB RAM, 2x 3com 905, SuSE. The other cluster serves site Anonymous FTP front for NFS mounted data on EMC Celerras and is similar to the other machines.
All machines are reclaimed - obsoleted from the desktop when we moved to Win2K. We moved to Linux for this service because SMB on Solaris is flaky as hell (our experience) and on HP-UX is slow slow slow.