Dell PowerVault ML6000 - Manual (Page 273)

Chapter 12 Installing, Removing, and Replacing
Adding 9U Library Expansion Modules to an Existing Library
Dell PowerVault ML6000 User’s Guide 273
a From the front of the library, open the I/E station and access
doors of the 9U Library Expansion Module.
b Squeeze the handle of the Y-rail release mechanism, lift it out of
its locked position, and slide it downward as far as it will go.
c
From the back of the library, find the rear Y-rail release
mechanism, which is located in the interior of the right side of the
module. Squeeze the handle of the Y-rail release mechanism, lift
it out of its locked position, and slide it downward as far as it will
go.
Doing this aligns the Y-rails with the Y-rails of the module
beneath it.
Caution:
Check to make sure that there is no gap between the top
and bottom Y-rails on both the front and back of the
library. If a gap exists, the library cannot mechanically
initialize.