IBM TotalStorage DS6000 Series Redbooks page 56

Second
expansion
enclosure
Server
enclosure
expansion
enclosure
expansion
enclosure
Figure 2-10 Switched disk expansion
DDMs
Each DDM is hot plugable and has two indicators. The green indicator shows disk activity
while the amber indicator is used with light path diagnostics to allow the customer to identify
and replace a failed DDM.
At present, the DS6000 allows the choice of four different DDM types:
73 GB, 15K RPM drive
146 GB, 10K RPM drive
146 GB, 15K RPM drive
300 GB, 10K RPM drive
All DDMs exist in what are called array sites. Array sites containing four DDMs are created as
DDMs are installed. During configuration discussed in Chapter 10, "DS CLI" on page 195, you
have the choice of creating a RAID-5 or RAID-10 array by choosing one or two array sites.
The first and the third array sites created on each loop each contribute one DDM to be a
32
DS6000 Series: Concepts and Architecture
Controller 0
First
Third
OUT ports to next enclosure
16
1
16
1
Controller 1
1
16
1
16
OUT ports to next enclosure
Up to 16 DDMs
per enclosure
Raid controller
DISK EXP ports
Internal
connections
through
midplane
Raid controller
DISK CONTRL
ports
Cables between
enclosures
Fibre channel
switches