IDC cabling-Data Center server access and deployment

The plane layout of data centers is usually in a rectangular structure. To ensure the cooling effect, 10 to 20 cabinets are usually placed back to back and discharged into one row to form a Cabinet group (also known as a POD ).

The cabinets in the POD adopt the ventilation mode before and after, and the cold air is sucked from the front panel of the cabinet and discharged from the rear. Thus, a "hot channel" is formed between the pods placed in the back-to-back of the Cabinet ", two Adjacent pods form a "Cold channel ".

The hot channel is facing CRAC (data center air conditioning), and the hot air streams back to CRAC along the hot channel, and then starts a new cycle.

Each POD consists of a server cabinet and a network Cabinet, with the majority of server cabinets. Due to the differences in the form of servers (rack servers and blade servers), there are also differences in the wiring methods of server cabinets and network cabinets in pods.

Rack server wiring:Vswitch EOR (End of Row) cabling

When the EOR mode of the switch is used, two network cabinets are placed at the edge of the two racks in each POD. All server cabinets in the POD are installed with distribution racks, the copper cables on the distribution frame extend to the network cabinet at the edge of the POD, and the access switch is installed in the network cabinet. The rack-mounted server is installed in the server cabinet, and the server Nic is connected to the distribution rack in the cabinet through a jumper (copper cable.

Vswitch EOR wiring features:Vswitch EOR is the most common wiring method.

Generally, before the server and access switch are installed, the cabling from the server Cabinet to the network cabinet has been completed, and the installation and jumper of the equipment (server/switch) are carried out in the server Cabinet and in the network cabinet. If the power of each rack-mounted server is 500 W and the power output of each server cabinet is calculated as 4 kW or 6 kW, 8-12 rack-mounted servers can be installed in a 42U server cabinet.

Disadvantages of EOR cabling:There are many copper cables (about 20-40 copper cables) from the server Cabinet to the network cabinet, and the copper cables of the server cabinet farther away from the network cabinet, the longer the wiring distance in the data room, as a result, the cable management and maintenance workload is large and the flexibility is poor.

The wiring of the switch MOR (Middle of Row) is an improvement on the EOR wiring mode. The MOR network cabinet is deployed in the middle of the POD's two-row cabinet, which can reduce the cable distance from the server Cabinet to the network cabinet and simplify the cable management and maintenance work.

Rack server wiring:Switch TOR (Top of Rack) cabling (real Deployment Solution for large data centers)

The TOR cabling mode of a switch is an extension of the EOR/MOR mode. When a TOR is used for cabling, one or two access switches are deployed at the top of each server cabinet in the POD, A rack-mounted server is connected to a switch in the cabinet through a jumper, And the uplink port of the switch is connected to the aggregation switch in the network cabinet of EOR/MOR through copper or light.

TOR wiring features:

TOR wiring simplifies the wiring between server cabinets and network cabinets. The number of optical fiber cables or copper cables (4-6) from each server Cabinet to EOR/MOR network cabinet is small ). The density of servers in the cabinet is high. For cabinets with a standard width of 19 inch and 42U, if the switch TOR is used for cabling, 15-30 rack servers with a 1U height can be deployed in each cabinet (the power consumption of a single server and the power output of the Cabinet must be considered ).

Disadvantages of TOR cabling:

Each server cabinet is limited by the power output power, and the number of servers that can be deployed is limited. As a result, the access port utilization of switches in the cabinet is insufficient.

One or two access switches are shared among several server cabinets, which can solve the problem of insufficient port utilization. However, this method increases the cable management workload. In terms of network design, there are not many VLANs on each access switch in TOR cabling mode. During network planning, we should also try to avoid a VLAN using a aggregation switch to connect multiple access switches, therefore, in a network topology using TOR cabling, the range of each VLAN is not too large, and the number of ports contained is not too large.

However, for the EOR cabling method, the port density of the access switch is high. When the network is initially designed, there may be VLANs with a large number of ports. The number of access switches in TOR mode is large, and the number of access switches in EOR mode is small. Therefore, the management and maintenance of network devices in TOR mode is heavy.

Wiring of blade servers

When installing a Cabinet, the blade server integrated with the blade switch does not need to consider the Jumper from the server in the cabinet to the access switch/or the distribution frame. You only need to consider the wiring method of the uplink port of the blade switch.

The rack-mounted server requires jumper connections for each server. For example, when a 42U server cabinet is installed with 10 1RU rack servers and one access switch, the following figure shows 22 power cables (redundant power supplies are configured for servers and switches), 10 kvmlines, and at least 30 twisted pair wires (two service NICs and one management Nic for each server ), two optical fiber cables (uplink ports of vswitches) are not included in the cables connecting external storage devices and other devices.

For a blade server with 10 server modules and 2 switch modules, only two power cords, one kvmline, and four optical fibers are required. Therefore, blade servers have obvious advantages over rack servers in Cabling Management of data centers.

The blade servers of the integrated switch module use the EOR/MOR wiring mode. However, the EOR wiring mode has the same characteristics as the rack-mounted server TOR wiring mode ,.

The server completes network access within the server cabinet. The cables from the server Cabinet to the EOR or MOR network cabinet are mainly light from the uplink convergence switch of the blade switch, and the number of cables is relatively small. However, the computing unit density of the blade server is higher than that of the rack-mounted server, so the power output power of a single cabinet and the cooling environment of the data center are also higher.

The Rack cabling mode of the blade server using the pass-through module can be divided into two types: EOR/MOR and TOR. The two types have the same characteristics as the rack-mounted server.