After T125827 we have run out of failovers for x1. A permanent solution will arrive at T158669, but it will be delayed a few weeks (codfw failover will happen earlier). We could pool some of the existing servers (the main ones for enwiki, commons, etc.), but for separation of resources I would prefer not to- a separate server, even if less powerful (not much resources are required), would be preferred for reliability reasons.
We need a small slave just in case of the worst case scenario happens: we only need 200G, do not need RAID or SSDs and 8 or 16 GB of RAM. And probably will never get used- except if a problem appears on the production machine.
We are bargaining for a spare for just 1 month's time, until the failover is done and the new boxes arrive.