Lenovo ThinkSystem Caddies - What Fits

Lenovo ThinkSystem carriers in stock

4 in-stock listings · both form factors · ranked by price per unit, not pack price · refreshed every few hours

What this part actually is

Carriers for Lenovo's ThinkSystem line. This is the thinnest market of the three vendors we cover, and prices reflect that - the spread between the cheapest and dearest listing for what sellers describe as the same part is wider here than anywhere else in this category, which is a reason to read the compatibility claim rather than sort by price.

A drive carrier — caddy, tray, sled, the words are used interchangeably — is the frame that holds a bare drive and lets it slide into a hot-swap bay and mate with the backplane connector. It is a piece of stamped metal and plastic with a pair of spring rails, and it is astonishing how much of a used-server build's cost it can represent. A twelve-bay chassis needs twelve of them. At roughly $9.95 each at today's cheapest listing, that is a real line in the budget, and it is the line most often left out of the mental arithmetic when someone sees a cheap server and thinks the job is done.

The reason you cannot simply reuse a carrier from another machine is that carriers are specific to a chassis generation. The screw pattern, the rail geometry, the position of the connector cut-out and the light-pipe that carries the activity LED from the backplane to the front of the tray all change between generations, and sometimes between form factors within one generation. A carrier that is 3mm wrong does not go in a little tight; it does not go in.

Carriers, blanks and why the difference matters

A chassis that arrives with all its bays looking occupied is not necessarily a chassis that arrives with carriers. Servers ship with blanks in unused bays — solid plastic fillers whose only job is to keep the airflow path closed so cooling works as designed. From the front, at listing-photograph resolution, a bay full of blanks looks very much like a bay full of trays.

A blank has no rails, no connector cut-out and nowhere to mount a drive. It cannot be converted. If a listing says “Lenovo server, all bays populated” and the photograph shows uniform featureless fronts with no drive-activity LED windows, assume blanks and ask. This single question is worth more than any other you can put to a seller of a used chassis, because it is the difference between a machine you can fill this weekend and a machine that needs another purchase before it does anything.

Part numbers, and what we will and will not tell you

Part number unverified — match by generation and bay size. We have not found a carrier part number for this generation in either tier. Lenovo's owner's and technical manuals describe carriers generically — “drives are supplied in hot-swappable carriers” — and publish no part number, and the aftermarket listings for this generation sell on model compatibility rather than on a number. Numbers do circulate on forums; we are not repeating them, because a carrier part number that is right for one generation and wrong for the next is a genuinely expensive mistake and we have no way to tell you which this is. Buy on the stated generation and form factor, from a seller who names the machines the part fits.

Buying in packs

This is the one category on this site where multi-packs are the sensible purchase and the table above is built around that. Elsewhere we exclude multi-pack listings, because a two-pack of hard drives distorts every price-per-terabyte comparison it appears in. Caddies are different: you need one per bay, so a four-pack or a ten-pack is how the part is genuinely sold and refusing to list them would hide most of the market.

The consequence is that pack price tells you nothing on its own, so the table sorts on price per caddy and highlights the cheapest per-unit figure rather than the cheapest sticker. A ten-pack at $70 beats a single at $9, and the ranking has to say so or it is actively misleading. Work out how many bays you are filling before you shop, because the per-unit price usually falls sharply with pack size and buying two four-packs to fill seven bays is a common and avoidable waste.

What to check when they arrive

Carriers are simple parts and most arrive fine, but they arrive in bulk and the failure modes are easy to miss until you are halfway through a build:

• The spring clips or rails. The tray latches into the bay under spring tension. A bent or fatigued rail lets a drive sit slightly proud of the backplane connector, which presents as a drive that intermittently disappears — one of the more maddening faults to diagnose because the drive itself tests fine.
• The light pipe. Most carriers carry a clear plastic pipe that brings the backplane's activity and fault LEDs to the front panel. A missing or broken one costs you nothing functionally and costs you the ability to see at a glance which drive has failed — which is exactly when you want it.
• The screws. Drives mount to the carrier with four screws, usually of a specific type and length. Listings vary on whether they are included, and a pack of carriers that arrives without them stops the build until more arrive. Check the listing text; do not assume.
• Fit one before you fill all of them. Mount a single drive, slide it in, confirm the machine sees it, and only then build out the rest. Discovering a fit problem once is a return; discovering it after mounting twelve drives is an evening.

Aftermarket or original?

Nearly everything in the table above is aftermarket, because that is what this market is — genuine vendor carriers in quantity, at retail, are not really a thing on the used market and where they exist they cost several times as much. The honest position is that aftermarket carriers are widely used and generally work, and that quality varies more than it does for original parts. The metal is sometimes thinner and the spring rails sometimes less durable, which matters most if you expect to swap drives frequently.

For an array that gets built once and then left alone, the aftermarket part is the rational buy and the saving is substantial. For a machine where drives come and go weekly, paying more for better rails is defensible. What we will not tell you is that one specific aftermarket brand is reliable and another is not — we have not tested them, and the brands in this market turn over too quickly for a claim like that to stay true.

Where this fits in the build

Carriers are one of three things people forget when budgeting a used server, alongside the drives themselves and the storage controller. The used server buyer's guides cover which bay configuration each machine was built in — which determines how many carriers you need and in which form factor — and the HBA and controller guide covers the card that has to be in the machine before any of those drives is useful for ZFS. For the drives, small-format bays are mostly a SAS and enterprise-SSD market — the cheap high-capacity drives are all large-format.

Other carrier generations

Dell 13th/14th generation 3.5" LFF · Dell 13th/14th generation 2.5" SFF · Dell 11th/12th generation · HPE Gen8/Gen9 2.5" SFF · HPE Gen8/Gen9 3.5" LFF · HPE Gen10