- Cooling: Densely packed rack mounted equipment is difficult to keep cool. Placing it in a cramped metal box will make this worse. Rack mounted equipment is usually designed to draw cool in air from the front and exhaust hot air out the back. This assumes there is a isle at the front and back for the air to circulate; a false floor underneath for the cool air to be delivered and space above the cabinets to carry the hot air away. An ISO shipping container is too small to do this in and most of the designs use only one isle down the middle with racks up against the side of the container. Photos of the Sun system show what appear to be very large cooling air ducts coming out of the front, which have to be ducted somewhere. Other units show doors in non standard places and lots of cables coming out of holes in the containers.
- Maintenance: The isle at the front and back of racks not only allows air to circualte, it also also provides space for maintenance workers to exchange equipment and run cables (there are a lot of cables in a data center). The width of an ISO container only allows for one narrow isle, making maintenance difficult.
- Delivery: Rack mounted cabinets are designed to fit in the back of a small truck or plane. There are trucks with special suspension designed to carry sensitive computer equipment. Only a few specialist cargo aircraft are large enough to carry an ISO container, so the boxes would have to long distances by sea, road or rail. The sea, road and rail transport systems designed to handle ISO shipping containers are not intended for delicate equipment and do not protect containers from the elements. The data center would need to be very well sealed for transport to prevent water damage and be sturdy enough top prevent damage from vibration, knocks and being tilted. The containers need to have enough room in them for staff to install and maintain the equipment, so about one third to one half of each container is empty, resulting in increased shipping costs.
- Installation: Rack mounted cabinets are designed to fit trough a space about the size and shape of a standing person, so they can be pushed through a normal doorway and into a passenger lift, using a simple handcart. The equipment is therefore compatible with office buildings. In contrast shipping containers require a very large fork lift truck to move them and will not fit in an ordinary office building. They would need a specially designed warehouse-like building or annex to a building. ISO shipping containers are designed to be weatherproof, but setting up a datacenter outdoors would require all of the conduits to be carefully sealed and make maintenance very difficult, as containments would enter every time a door was opened. There have been many modular building systems based on ISO containers which have failed due to leaks. Having a container crammed with sensitive electrical equipment in a leaky steel box would be disastrous. Also the average corporation does not want to have something which looks like a container wharf or an electricity substation, next to their office building. The plan for a major data center in Canberra is in jeopardy due to opposition to the collocated power station. A containerized data center is likely to draw planning objections.
- Safety: Data center equipment is designed to be maintained with the power switched on. Staff need to be able to replace one computer in a rack, while the rest of the equipment keeps working. Working in a cramped metal box will be far less safe than a traditional data center. There will be less room for the staff to work and the walls will form one sealed electrically conductive box. Noise from the equipment is likely to be higher than in a normal room. As the box is designed to be sealed, it will need to have vents added to allow for fire fighting. If inert gas firefighting is used, it will be deadlier than in a conventional room and there will be fewer escape exits. Staff may have less than a minute to escape before being killed by the fire suppression system.
An alternative o the shipping container data center, I suggested some time ago, is a pallet data warehouse. With this the computers would be mounted on standard shipping pallets. The pallets would be simply placed on the floor. For very high density installations they could be stacked in a warehouse-like building using small fork lift trucks. Pallets are designed to fit in small trucks and aircraft . Smaller ISO pallets are designed to fit through a doorway and in a passenger lift. ISO pallets are designed to fit in ISO shipping containers and so these could be used for transport, with additional protective packing around the pallets. If needed, a shipping container data center could be build by wiring up the palletized equipment in a container.