I have worked in many multi-vendor data centers (not Google scale, just bank, insurance co size). Admittedly my experience is multi-OS: HPUX, AIX, Solaris + so

I have worked in many multi-vendor data centers (not Google scale, just bank, insurance co size). Admittedly my experience is multi-OS: HPUX, AIX, Solaris + some Linux. Compared to the cost of equipment the cost of designing and documenting each rack, along with IP addresses, SAN and fibre-channel, top of rack switches, directors, etc, is only a small fraction. We used to bench build each and every server to design specs and only loaded it into the rack when it was verified to be correctly configured. Upon first power-up we would verify that the management consoles could correctly see the servers and all their configured interfaces, i.e. all NICs and FCAs.