Best Brands for Reliable SAS Enclosures, and How to Choose One

There is no single best brand of SAS enclosure. Reliability comes from the design of the shelf (two I/O modules, redundant power, hot-swap everything) and from pairing it with a controller its vendor actually supports. The mainstream choices are Dell EMC PowerVault, HPE D-Series, Lenovo ThinkSystem, NetApp DS shelves and Supermicro JBODs, and each is the right answer for a different estate. This guide explains how to choose, using the 12Gb/s SAS enclosures Nexus Compute supplies as worked examples.

Which brands make reliable SAS enclosures?

• Dell EMC PowerVault MD1400: 12 x 3.5-inch bays in 2U with dual EMMs (enclosure management modules). The natural expansion shelf for PowerEdge servers with a Dell external RAID controller or SAS HBA.
• HPE D3600: 12 x 3.5-inch bays in 2U with dual I/O modules, qualified for HPE ProLiant and MSA platforms.
• Lenovo ThinkSystem D1212: 12 x 3.5-inch bays in 2U with dual ESMs, qualified for Lenovo ThinkSystem DE and SR series.
• NetApp DS224C: 24 x 2.5-inch bays in 2U with dual IOM12 modules, qualified for NetApp FAS, AFF and E-Series. Treat it as capacity for a NetApp system, not as a general-purpose server JBOD.
• Supermicro CSE-846BE1C-R1K23JBOD and CSE-847E1C-R1K28JBOD: 24 and 45 x 3.5-inch bays in 4U, single expander. Host-agnostic and dense, the usual pick for software-defined storage on mixed hardware.

Every enclosure above is a 19-inch rack-mount unit with 12Gb/s SAS and redundant power supplies, and all of them are sound. The differences in how they are supported matter more than differences in build quality, which is why it pays to choose by what the shelf will attach to. A vendor shelf behind that vendor's controller, on firmware the vendor has tested together, is a known configuration with one support path. The same shelf behind an unqualified controller may run perfectly well, but when a drive drops out at 2 a.m., nobody's support matrix covers it.

What actually makes a SAS enclosure reliable?

• Dual I/O modules. Dell calls them EMMs, HPE calls them I/O modules, Lenovo ESMs and NetApp IOMs. Two modules give every drive two independent paths to the host, so a failed module, cable or HBA port does not take the shelf offline.
• Dual-ported drives. SAS drives have two ports, one for each I/O module. SATA drives have one, so a dual-module shelf full of SATA drives does not give those drives path redundancy.
• Redundant, hot-swap power. Feed the two supplies from separate PDUs on separate circuits, or the redundancy is only half there.
• Enclosure management. SES (SCSI Enclosure Services) reports fan, temperature, power and slot status to the host, so a failed drive raises an alert and lights the right fault LED.
• A supported firmware set. Enclosure, expander, controller and drive firmware should be a combination the vendor has qualified, and kept that way through updates.

Single expander or dual I/O modules: which do you need?

The two Supermicro JBODs listed here are single-expander designs with redundant power. That means one data path from the host to the drives. It is a reasonable choice for software-defined storage that replicates or erasure-codes across nodes (Ceph, object storage, backup repositories), where a whole enclosure going offline is an event the software already handles. It is the wrong choice for a shelf that holds the only copy of the data behind one host. There, buy dual I/O modules, populate them with dual-ported SAS drives, cable two HBA ports to the two modules, and enable multipath on the host. Supermicro also builds dual-expander versions of its JBOD chassis, so if you want Supermicro density with two paths, specify that before ordering rather than assuming it.

Should you choose 2.5-inch or 3.5-inch bays?

Pick the bay size from the drives, not the other way round. 3.5-inch bays are for high-capacity nearline server hard drives, where cost per terabyte and terabytes per rack unit drive the decision. The Supermicro CSE-847E1C-R1K28JBOD is the densest 3.5-inch option here, with 45 bays in 4U, against 24 bays in 4U for the CSE-846 and 12 bays in 2U for the MD1400, D3600 and D1212. 2.5-inch bays suit SSDs and performance SAS drives, where you want more devices per rack unit: the NetApp DS224C fits 24 in 2U, and HPE's MSA 2060 24-bay SFF drive enclosure does the same job for MSA 2060 arrays.

Does 12Gb/s SAS matter if you are filling it with hard drives?

Per drive, rarely. At the uplink, often. An expander shares a limited number of host lanes across every bay, and a standard external x4 wide port at 12Gb/s per lane carries 48Gb/s raw. A shelf of HDDs streaming sequentially can approach that, and a shelf of SSDs will exceed it. For dense or flash-heavy enclosures, cable more host ports or spread drives across more shelves. 12Gb/s SAS enclosures also accept 6Gb/s SAS devices, which then run at their own lower link rate.

Should you put an HBA or a RAID controller in front of it?

Use an HBA when the software owns the disks: ZFS, Ceph, Windows Storage Spaces, backup appliances and anything else that wants raw drives and its own view of drive health. Use a RAID controller with external ports when the host operating system needs a protected volume and you want hardware RAID with a protected write cache. Our guide to RAID vs HBA controllers covers the trade-offs in detail. With vendor shelves, the controller is part of the qualification. Dell, HPE and Lenovo each publish which of their own controllers support each enclosure, and NetApp shelves attach to NetApp controllers. Supermicro JBODs are the flexible option: they work with standard 12Gb/s SAS HBAs that have external ports.

How do you cable and chain SAS enclosures?

• Connectors: external 12Gb/s SAS normally uses Mini-SAS HD (SFF-8644) on the HBA and on the enclosure I/O modules. Confirm the connector at both ends before ordering cables.
• Redundant cabling: run host port A to I/O module A and host port B to module B, ideally from two different HBAs, then enable multipath (dm-multipath on Linux, MPIO on Windows) so the OS sees one device per drive.
• Daisy-chaining: shelves chain through the expansion ports on each module. Every vendor sets a maximum number of shelves per chain and per controller, so check it for your controller before planning growth.
• Cable length: passive copper SAS cables are short. Runs between racks may need active or optical cables that the controller vendor supports.
• Interface check: not everything labelled a storage enclosure is a SAS JBOD. Internal drive cages, PCIe carriers, legacy SCSI units and USB-attached expansion boxes (such as QNAP's 10Gbps JBOD expansion units) sit alongside SAS shelves. Filter by interface, and check that the listing states SAS as the drive interface.

Which SAS enclosure should you buy?

• PowerEdge estate: the Dell EMC PowerVault MD1400, behind a Dell external controller.
• ProLiant or MSA estate: the HPE D3600, or the MSA 2060 SFF drive enclosure to add 2.5-inch capacity to an MSA 2060.
• ThinkSystem SR or DE estate: the Lenovo ThinkSystem D1212.
• Existing NetApp FAS, AFF or E-Series system: the NetApp DS224C, and only for that purpose.
• Software-defined storage on mixed or whitebox servers, maximum 3.5-inch density, and software that tolerates a single path: the Supermicro CSE-846BE1C-R1K23JBOD or CSE-847E1C-R1K28JBOD.

Reliability is a property of the whole path: dual-ported drives, two I/O modules, two cables, two host ports and multipath on the host. Buy the enclosure your controller vendor supports, and the brand question mostly answers itself.

Nexus Compute supplies these enclosures new, sourced through authorized distribution with the full manufacturer warranty, and checks the shelf, controller and drive combination against your platform before dispatch. Send the server model, the controller and the drive plan through request a quote and we will reply within 48 business hours.