Dell EMC Unity Series Field Upgrade Procedure page 8

Field Upgrade Procedure
Adding the new 80-drive DAE
Choosing where to install the DAE
Special considerations for adding an 80-drive DAE
Unity All Flash and Unity Hybrid Field Upgrade Procedure
8
Take the following actions to install the new 80-drive DAE into the system.
Before installing the new DAE, you should determine the placement of the new
enclosure within the rack.
Choose a 3U space in the rack for the new DAE after reviewing the following
guidelines:
Leave 1U of space at the bottom of the rack for access to cables.
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Populate all 80-drive DAEs starting from the bottom of the rack before adding
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DPEs and other DAEs.
CAUTION
Improper positioning of the 80-drive DAE may cause the cabinet to become
top-heavy and susceptible to falling.
If there is already an 80-drive DAE in the rack, place the new DAE directly above
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the existing DAE.
When adding a 80-drive DAE to an existing installation, ensure that a 25-slot DAE,
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15-slot DAE, or the DPE itself, is not positioned between two 80-drive DAEs. If the
DAE is improperly positioned, it causes a serviceability tunnel and makes servicing
the DPE or DAEs difficult.
The 80-drive DAE supports back-end x8 cabling. However, special steps must be
taken before powering on the system.
If you are connecting the DAE to a 4-port SAS SLIC that requires x8 connectivity,
insert the SAS cable into the 4-port SAS SLIC before persisting the SLIC. The 4-port
SAS SLIC must be persisted with the cable inserted for x8 connectivity.
Note
If the SAS back-end SLIC is powered on without any cables inserted, it is
automatically set at x4 and cannot be used for x8 lane cabling.
80-drive DAE and SLIC port mapping information
BE 0 and 1 can only be x4 and thus will always be back end (BE) 0 and 1.
15-drive, 25-drive and 80-drive DAEs are all valid configurations when connected to
BE 0 and/or 1 as x4.
SLIC BE ports 2 through 5 can be either x4 or x8. They will persist at the time of the
install. To persist x8, at the very least the x8 cable must be in place. The x4 cable does
not have to be in place to be x4.
15-drive, 25-drive and 80-drive DAEs are all valid configurations when connected to
BE 2 through 5 as x4. If they are x4 they will map to BE 2, 3, 4 and 5. If they are x8
they will map to 2 and 4. Only 80-drive DAEs can be connected x8 to BE 2 or 4
therefore an x8 80-drive DAE will always be on either BE 2 or 4.