IBM Storwize V5000E Quick Installation Manual page 80

• SAS cables must be routed through the cable management arms to reduce the risk of disconnecting the
nodes from their storage arrays. This step also helps to protect the SAS cables from getting damaged if
you slide the node or enclosure out of the rack while they are attached. Arrange your cables to provide
access to the following components:
– Ethernet ports, including the technician port. The technician port is used for initial setup of the
system by directly attaching to a personal computer. It can also be used to complete service actions
for the system.
– USB ports. USB ports can be used to initialize the system or to perform service-related tasks by using
a USB flash drive that contains executable files for initializing the system.
– Fibre Channel and Fibre Channel over Ethernet (FCoE) ports. If your system has an optionally
installed Fibre Channel and FCoE adapter for host and external storage attachment, ensure that
these ports are accessible.
Note: Some control enclosures do not support FCoE connections
– Fibre Channel ports. If your system has an optionally installed Fibre Channel adapter for host and
external storage attachment, ensure that these ports are accessible.
– The nodes and the enclosures themselves. Access is required to the hardware for servicing and for
safely removing and replacing components by using two or more people.
Combining 2U and 5U expansion enclosures
About this task
You can combine 2U and 5U enclosures in a SAS chain. The limiting factor is the combined chain weight of
the various components. The maximum SAS chain weight that can be attached to a node SAS port is 10:
• 5U expansion enclosures have a chain weight of 2.5
• 2U expansion enclosures have a chain weight of 1.
Example
Table 28 on page 56 shows example of different combinations of SAS weights.
Table 28. Example combinations of supported SAS chains and expansion enclosures
2U Enclosures (12
drives)
2
2
0
1
In addition, the location and orientation of the Input and Output SAS ports on the 2U and 5U SAS
enclosures differs. Figure 56 on page 57 shows the SAS ports on the 2U and 5U expansion enclosures.
56 IBM Storwize V5000E : Storwize V5000E Quick Installation Guide
2U Enclosures (24
drives)
0
3
7
1
5U Enclosures (92
drives)
3
2
1
1
Combined Chain
Weight
9.5
10
9.5
4.5