In the initial installation of the DS5020, you can add only new storage expansion
enclosures to the DS5020 storage subsystem. This means there must be no
existing configuration information about the storage expansion enclosures that you
want to install.
The DS5020 supports the attachment of up to six EXP520 and EXP810 storage
expansion enclosures, resulting in the capability to connect up to 112 E-DDMs and
enabling storage configurations of over 49 TB using 450 GB Fibre Channel E-DDMs
or 112TB using 1 TB SATA E-DDMs.
The base DS5020 storage subsystem supports up to 32 drives, which includes 16
drives in the DS5020 chassis and 16 more drives in an attached storage expansion
enclosure. Toattach more than 32 drives, you much purchase the applicable
feature option.
Toattach additional drives to the DS5020, you can use EXP520 or EXP810 storage
expansion enclosures. Youcan connect EXP520 storage expansion enclosures to
the DS5020 without purchasing feature options. Toattach an EXP810 storage
expansion enclosure or enclosures to the DS5020, you must purchase the Attach
EXP810 to DS5020 Activation feature option. Contact your IBM marketing
representative or IBM reseller for more information.
Toconnect 33 - 64 drives in one DS5020 and three EXP520 storage expansion
enclosures, you must purchase the DS5020 Drive Attach 33 - 64 feature option. If
you need to connect 65 - 112 drives in a DS5020 configuration, you must purchase
the DS5020 Drive Attach 65- 112feature option in addition to the DS5020 Drive
Attach 33 - 64 feature option. These two feature options enable you to attach the
additional drives in one DS5020 and six EXP520 storage expansion enclosures.
Contact your IBM marketing representative or IBM reseller for more information.
If the storage expansion enclosures that you want to install currently contain logical
drives or configured hot spares, and you want them to be a part of the DS5020
storage subsystem configuration, refer to the IBM System Storage DS4000 Hard
Drive and Storage Expansion Enclosure Installation and Migration Guide. Improper
drive migration might cause loss of configuration and other storage subsystem
problems. Contact your IBM technical support representative for additional
information.
Redundant drive channel pair
Each controller on the DS5020 has drive channel ports. The storage expansion
enclosures that are connected to these ports form a drive channel (also referred to
as drive loop). The maximum number of hard drives that can be installed in one
drive channel is 112. One drive channel from each controller combines to form a
redundant drive channel pair.
Figure 35 on page 56 shows an example of a redundant drive channel pair.If any
component of the drive channel fails, the RAID controllers can still access the
storage expansion enclosures in the redundant drive channel pair.
Note: In the following drive cabling figures, the DS5020 graphics are simplified to
show only the drive ports of each controller.
Chapter3. Cabling the storage subsystem 55