EMC VNX Series Hardware Information Manual page 72

Disk-array enclosure
Drive carrier
Disk drives
Midplane
LCCs
72 VNX5500 Hardware Information Guide
In a 2U and 3U DAE, the disk drive carriers are metal and plastic assemblies that provide
smooth, reliable contact with the enclosure slot guides and midplane connectors. Each
carrier has a handle with a latch and spring clips. The latch holds the disk drive in place to
ensure proper connection with the midplane. Disk drive activity/fault LEDs are integrated
into the carrier (Figure 64 on page 74
For more information about the drive carrier in a 4U DAE, see the
DAE"section on page 88.
Each disk drive consists of one disk drive in a the 2U or 3U carrier. You can visually
distinguish between disk types by their different latch and handle mechanisms and by
type, capacity, and speed labels on each disk drive. You can add or remove a disk drive
while the DAE is powered up, but you should exercise special care when removing disk
drive while they are in use. Disk drives are extremely sensitive electronic components.
IMPORTANT
The 4U DAE cannot use disk drives from a 2U or 3U DAE. The 4U DAE employs different
types of SAS, NL-SAS, or Flash disk drives.
In a 2U or 3U DAE, a midplane separates the front-facing disk drives from the rear-facing
LCCs and power supply/cooling modules. It distributes power and signals to all
components in the enclosure. LCCs, power supply/cooling modules, and disk drives plug
directly into the midplane.
In a 2U or 3U DAE, an LCC supports, controls, and monitors the DAE, and is the primary
interconnect management element. Each LCC includes connectors for input and
expansion to downstream devices. An enclosure address (EA) indicator is located on each
LCC (Figure 70 on page 80
identification indicator (Figure 70 on page 80
In a 4U DAE, the primary functionality of an LCC is to be a SAS expander as well as to
provide enclosure services to all the disk drives (60 in all). In other words, the LCC in a 4U
DAE ("LCC" on page 94) implements a version of the Common Disk Enclosure Sub-system
(CDES) architecture. CDES consists of the PMC-Sierra PM8005 SXP 6G SAS expander, the
Common Disk Enclosure FPGA (CDEF) and supporting logic.
In the 4U DAE LCC, two SAS expanders are available. As previously described, the SAS
expanders are PMC-Sierra SXP36 6G (PM8005, rev C) components. Each expander
functions or operates separately. That is, each expander has its own CDEF and supporting
logic to support 30 drives each. A 4-lane SAS wide port connecting each expander to the
1. The EA is sometimes referred to as an enclosure ID.
and Figure 71 on page
and Figure 77 on page 87)
and Figure 77 on page
81).
"4U, 60 (2.5- or 3.5-inch)
1
. Each LCC includes a bus (loop)
87).