Non-Trunking Cabling; Example Of Redundant Drive Channel Pairs; Maximum Number Of Drives Per Drive Channel By Enclosure Type - IBM DS5100 Installation, User's, And Maintenance Manual

In Figure 35, drive channel 1 of controller A and drive channel 5 of controller B
combine to form a DS5100 and DS5300 drive channel pair. If any component of
drive channel 1 fails, the RAID controllers can still access the storage expansion
enclosures in drive channel 1 through drive channel 5. Similarly, drive channel 2 of
controller A and drive channel 6 of controller B combine to form the second of the
two DS5100 and DS5300 drive channel pairs. If any component of drive channel 2
fails, the RAID controllers can still access the storage expansion enclosures in drive
channel 2 through drive channel 6.
Figure 35 shows the storage expansion enclosures in each drive channel pairs
connected to only one drive port in the two-ported drive channel. For example, in
drive channel pair 1, only port 8 of channel 1 and port 1 of channel 5 are used.
Note: In the following drive cabling figure, the DS5100 and DS5300 graphic is
Figure 35. Example of redundant drive channel pairs

Non-trunking cabling

Non-trunking cabling is the cabling scheme where the controller drive ports are
connected to the EXP5000 or EXP5060 drive channel ports labeled 1B on both
ESMs of the EXP5000 or EXP5060 storage expansion enclosures, forming a pair of
redundant connections between the storage subsystem and the storage expansion
enclosure. This is the cabling that is supported when intermixing the EXP5060 and
EXP5000 or EXP810 storage expansion enclosures behind the same drive channel
or drive channel port.
Table 17. Maximum number of drives per drive channel by enclosure type
Storage expansion
enclosure
EXP5000
EXP5060
EXP5000 and EXP5060
simplified to show only the drive ports of each controller. The storage
expansion enclosures are simplified to show only the ESM FC ports.
Left ESM
DS5000 Controller B
Left ESM Left ESM
Maximum number of drives
112
120
108
Right ESM
DS5000 Controller A
Right ESM
ds50075
Chapter 3. Cabling the storage subsystem
Number of storage
expansion enclosures
7 EXP5000
2 EXP5060
1 EXP5060 and 3 EXP5000
Redundant drive
channel pair 1
61