IBM NED24 NVMe Expansion Drawer
What the NED24 NVMe expansion drawer is, how many a Power 11 system can attach, and when a drawer is the right answer instead of larger internal drives or external FlashSystem storage.
The NED24 is IBM's NVMe expansion drawer for Power 11: direct-attached flash capacity that extends a system past the drive bays in its own chassis. It is the answer to a specific problem, which is a machine with plenty of processor and memory headroom that has run out of somewhere to put data. It is not a general-purpose storage tier and it is not a substitute for a SAN.
How many NED24 drawers each Power 11 model takes
NED24 support across the Power 11 line
| Model | Machine type | NED24 drawers | Internal NVMe before expansion |
|---|---|---|---|
| S1112 | 9242-21B / 21T | Not supported | 12.8 TB across 4 slots |
| S1122 | 9824-22A | 1 | 122.4 TB (8x 15.3 TB) or 51.2 TB (8x 6.4 TB) |
| S1124 | 9824-42A | 2 | 244.8 TB (16x 15.3 TB) or 102.4 TB (16x 6.4 TB) |
| L1122 | 9856-22H | 1 | 122.4 TB (8x 15.3 TB) or 51.2 TB (8x 6.4 TB) |
| L1124 | 9856-42H | 1 | 244.8 TB (16x 15.3 TB) or 102.4 TB (16x 6.4 TB) |
| E1150 | 9043-MRU | Up to 4 per node | 153 TB (10x 15.3 TB) or 64 TB (16x 6.4 TB) per node |
| E1180 | 9080-HEU | Up to 4 per node | 102.4 TB per node (16x 6.4 TB) or 30.6 TB (2x 15.3 TB) |
The L1124 takes one NED24 where the otherwise-equivalent S1124 takes two. That is a real difference between two machine types that match on nearly everything else, and it is easy to miss when comparing them on a spec sheet.
Drawer, bigger drives, or external storage
Larger internal drives first
If the chassis is populated with 6.4 TB drives, moving to 15.3 TB roughly triples internal capacity with no drawer, no rack space and no extra cabling. Check what is actually installed before pricing expansion ... plenty of systems are nowhere near their internal ceiling.
A NED24 when you need raw local flash
The drawer earns its place when internal bays are genuinely full and the workload wants direct-attached NVMe latency rather than a fabric hop. It adds capacity to one system, which is both the point and the limitation.
FlashSystem when more than one machine needs it
External FlashSystem storage costs more to introduce and gives you shared capacity, snapshots, replication and a data services layer that a direct-attached drawer does not have. If a second system will ever want the same data, start there instead.
Rack and power planning
Each drawer is physical: rack units, power feed and cabling. On a machine that supports four per node, a fully expanded configuration is a facilities question as much as a storage one.
NED24 drawer support is a property of the machine type, not the model family. The S1112 supports no NED24 at all and is limited to its 4 internal slots plus half a Gen4 I/O expansion drawer when rack-mounted. If an entry system needs real flash growth, that constraint usually decides the machine type rather than the other way around.
Related
Per-model storage ceilings are on the Power 11 specs page, and the drawer listing is at NED24 NVMe expansion drawer. For the shared-storage comparison see FlashSystem external storage for Power 11. The short definition is at NED24 in the glossary.