Chapter 2. System overview 25
Figure 2-7 shows a dense expansion drawer.
Figure 2-7   IBM dense expansion drawer
2.5.9  Expansion Enclosures
The following types of Expansion Enclosures are available:
/SM590000IBM Storwize V7000 large form factor (LFF) Expansion Enclosure Model 12F 
/SM590000IBM Storwize V7000 small form factor (SFF) 24F
IBM Storwize V7000 Gen2 LFF 12F includes the following components:
/SM590000Two expansion canisters
/SM59000012 Gb SAS ports for control enclosure and Expansion Enclosure attachment
/SM590000A total of 12 slots for 3.5-inch SAS drives
/SM5900002U, 19-inch rack mount enclosure with AC power supplies
IBM Storwize V7000 SFF Expansion Enclosure Model 24F includes the following 
components:
/SM590000Two expansion canisters
/SM59000012 Gb SAS ports for control enclosure and expansion enclosure attachment
/SM590000A total of 24 slots for 2.5-inch SAS drives
/SM5900002U, 19-inch rack mount enclosure with AC power supplies
The Expansion Enclosure is a 2U enclosure that includes the following components:
/SM590000A total of 24 2.5-inch drives (HDDs or SSDs).
/SM590000Two Storage Bridge Bay (SBB)-compliant enclosure services manager (ESM) canisters.
/SM590000Two fan assemblies, which mount between the drive midplane and the Node Canisters. 
Each fan module is removable when the Node Canister is removed.
/SM590000Two Power supplies.
/SM590000RS232 port on the back panel (3.5 mm stereo jack), which is used for configuration during 
manufacturing.