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One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchThe Cisco UCSC-SAS-M5HD is not a hardware RAID controller. It is a 12G SAS host bus adapter (HBA) that presents individual SAS and SATA disks in JBOD/pass-through mode. For Cisco-supported hardware RAID in a C240 M5 SX, the relevant replacement is UCSC-RAID-M5HD. Keep the HBA when ZFS, Ceph, Linux software RAID, Storage Spaces or another storage layer must control individual drives.
Identify the adapter and server first
UCSC-SAS-M5HD is installed in the C240 M5 internal storage-controller position and connects the SAS/SATA backplane to the operating system. Cisco’s specification describes it as JBOD-only and positions it for software-defined storage: C240 M5 SFF specifications.
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The M5HD controller family is associated with the UCSC-C240-M5SX, the 24-drive SFF version. Its physical arrangement is up to 24 front-loading drives plus two rear drives. Cisco documentation also calls this “up to 26 internal drives”; those figures describe the same chassis layout, not different controller limits. Confirm the exact chassis PID, backplane, cable set and drive technology before ordering.
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Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →| Server variant | Storage-controller context |
|---|---|
| UCSC-C240-M5SX | 24 front SFF bays plus two rear bays; M5HD HBA/RAID family |
| UCSC-C240-M5SN | Different 24-drive/NVMe-oriented design; uses the non-HD SAS/SATA controller family |
| UCSC-C240-M5S | Eight-drive SFF configuration |
| UCSC-C240-M5L | 12-drive LFF configuration |
Use Cisco’s C240 M5 installation and service documentation to verify the supported combination.
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UCSC-SAS-M5HD versus the Cisco RAID controller
| Adapter | Role | Hardware RAID | Internal C240 M5 SX drives |
|---|---|---|---|
| UCSC-SAS-M5HD | 12G SAS HBA; JBOD/pass-through | None | Up to 24 front plus two rear |
| UCSC-RAID-M5HD | 12G SAS RAID controller | RAID 0, 1, 5, 6, 10, 50, 60 and JBOD | Up to 24 front plus two rear |
With the HBA, the operating system sees disks individually. Your storage software performs redundancy, checksums, rebuilds and data placement. With the RAID controller, the adapter creates virtual drives and normally presents those logical volumes instead of individual members.
Choose the architecture that matches the workload
Keep the HBA for software-defined storage
- ZFS: direct disks allow ZFS mirrors or RAIDZ to manage checksums and recovery.
- Ceph: OSDs generally need direct device visibility; an HBA avoids an intervening hardware-RAID layer.
- Linux software RAID:
mdadmcan build and rebuild arrays from the exposed drives. - Windows Storage Spaces: Storage Spaces can own pooling and resiliency.
- Virtualization and distributed platforms: vSAN-like or other SDS designs may require individual-disk access; verify the platform’s hardware compatibility list.
These are architectural use cases, not a blanket Cisco certification for every software release or topology.
Use UCSC-RAID-M5HD for controller-managed virtual disks
Choose the RAID controller when a conventional operating system or hypervisor should receive logical volumes, when you need controller-managed RAID 5/6/10/50/60, or when write-back cache is part of the design. Cisco specifies 4 GB cache and optional flash-backed protection using the appropriate supercapacitor accessory. Cache protection health determines whether safe write-back is available; do not disable protection merely to recover benchmark speed.
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1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsUse an external HBA for external shelves
UCSC-9400-8E is a separate external SAS HBA for attaching external JBOD. Cisco lists support for up to 1,024 external SAS/SATA drives. It does not turn the internal UCSC-SAS-M5HD into a RAID card and does not create RAID for the C240’s front bays. Check the required external copper cabling and compatible enclosure in Cisco’s documentation.
RAID levels available on UCSC-RAID-M5HD
| Level | Fault tolerance and use |
|---|---|
| RAID 0 | No redundancy; a single disk failure loses the virtual disk. Use only for disposable data. |
| RAID 1 | Two-disk mirror; useful for an operating-system or small data volume. |
| RAID 5 | One-disk fault tolerance, but parity writes and long rebuilds make it less attractive for large or busy arrays. |
| RAID 6 | Two-disk fault tolerance; generally safer for high-capacity groups. |
| RAID 10 | Mirrored stripes with strong random-I/O and rebuild behavior, at roughly half the raw capacity. |
| RAID 50/60 | Striped RAID 5/6 groups; can improve scale but adds layout and rebuild complexity. |
Choose based on drive type, capacity, workload, rebuild time and the requirements of the operating system. RAID is not a backup.
Can both M5HD adapters be installed?
Treat this as a replacement decision, not an assumed dual-controller upgrade. Cisco describes one PCIe-style SAS RAID or HBA controller in the dedicated internal storage-controller socket. The normal supported approach is to replace UCSC-SAS-M5HD with UCSC-RAID-M5HD when hardware RAID is required. A separate external adapter is a different use case and does not share the internal backplane position.
Internal cabling in the 24-drive C240 M5 SX
For the primary front backplane, Cisco documents three cable groups:
| Group | Connections | Purpose |
|---|---|---|
| Cable A | Controller A1/A2 to backplane CONN-A | Front-backplane link group |
| Cable B | Controller B1/B2 to backplane CONN-B | Front-backplane link group |
| Cable C | Controller C1/C2 to backplane CONN-C | Front-backplane link group |
| Cable D (optional) | Controller reverse-side D1 to rear backplane | Rear-drive bays |
A missing or misrouted cable can look like a failed controller by hiding an entire group of drives. Follow the connector labels in the Cisco installation guide.
Replacing the controller safely
- Record the server PID, CIMC and BIOS versions, controller firmware, drive-slot order, virtual-disk names, RAID level, stripe size and cache policy.
- Back up data and export any controller configuration that your management tools provide.
- Confirm that the replacement is a Cisco-supported M5HD part for the C240 M5 SX, not merely a card with a similar connector.
- Power down, observe electrostatic precautions, replace the controller and reconnect every A/B/C cable; reconnect Cable D if rear bays are used.
- Enter CIMC or UCS Manager and check controller and drive discovery before changing any configuration.
- For a server in standalone mode, run the Cisco UCS Host Upgrade Utility (HUU) for the installed firmware release after the hardware swap. Cisco requires this even when displayed current and update versions appear identical because HUU programs the correct sub-OEM identity. Skipping it can cause incorrect drive enumeration.
- Verify CIMC, BIOS and storage-controller firmware compatibility. The HUU requirement does not apply in the same way to systems managed through UCS Manager.
- If an existing array is present, look for a foreign configuration and import it only after confirming the member slots and metadata. Do not initialize, clear or create new virtual disks until you know the old data is no longer needed.
- Validate boot order, virtual-disk visibility and operating-system discovery, then monitor all drives for errors.
NVMe and M.2 are separate storage paths
UCSC-SAS-M5HD and UCSC-RAID-M5HD control SAS/SATA devices. NVMe SSDs use PCIe and cannot be controlled by a SAS/SATA RAID controller, as Cisco explains in the C240 M5 platform guide. Replacing the HBA with the RAID card will not solve an NVMe visibility or NVMe RAID problem.
The optional Cisco Boot-Optimized M.2 RAID Controller module provides RAID 1 for two SATA M.2 devices. That protects a boot or hypervisor volume; it does not provide RAID for the front-loading SAS/SATA bays.
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Third-party cards and used-market checks
A Broadcom or LSI adapter may be electrically similar yet unsupported in a Cisco server. Verify Cisco firmware and sub-OEM identification, CIMC/BIOS discovery, HUU compatibility, cable and backplane pinout, and the support status of the exact PID. “Boots and sees disks” is not the same as a Cisco-supported production configuration.
When buying used equipment, confirm:
- Exact PID: UCSC-SAS-M5HD or UCSC-RAID-M5HD—not a listing that merely says “SAS RAID card.”
- Cache size and the included, healthy supercapacitor or flash-backed protection module.
- Firmware version, Cisco identity, return policy and tested drive discovery.
- Compatibility with the C240 M5 SX backplane and internal cable set.
- Drive qualification, sector format, firmware, SAS/SATA mixing rules and any SED key-management requirements.
Cisco lists these accessories in an end-of-sale notice, so new-stock availability is limited and secondary-market condition varies: Cisco UCS accessories end-of-sale information. No stable current list price should be assumed.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Troubleshooting by symptom
No hardware-RAID menu appears
This is normal with UCSC-SAS-M5HD: it is JBOD/pass-through. Use software RAID/SDS or install the supported UCSC-RAID-M5HD.
Only some front drives appear
Check the C240 M5 SX PID, controller seating, all A/B/C cable groups, Cable D for rear bays, backplane connections and firmware. If the controller was replaced in standalone mode, complete HUU before concluding that hardware is defective.
Drive count is wrong after a replacement
Recheck HUU completion and sub-OEM programming, then inspect cable routing and CIMC discovery. Cisco identifies the HUU step as necessary for correct enumeration in standalone mode.
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NVMe drives are missing
They are on PCIe/NVMe paths, not the SAS/SATA controller path. Use the server’s documented NVMe configuration instead.
Cache protection warning or slow writes
Check supercapacitor health and whether the controller switched from write-back to write-through. Investigate RAID level, rebuild activity, drive errors, thermal throttling and rebuild-rate settings before blaming the controller.
Foreign configuration is shown
Preserve the metadata, record slot order and confirm the replacement controller can import it. Never clear foreign configuration or initialize disks until backups and recovery requirements are settled.
Decision matrix
| Requirement | Best fit |
|---|---|
| ZFS, Ceph, Linux software RAID or direct-disk SDS | UCSC-SAS-M5HD |
| Controller-created RAID 1/5/6/10/50/60 virtual disks | UCSC-RAID-M5HD |
| Two SATA M.2 boot devices mirrored | Cisco Boot-Optimized M.2 RAID Controller |
| External SAS/SATA disk shelf | UCSC-9400-8E plus a compatible JBOD |
| NVMe RAID or NVMe disk management | PCIe/NVMe-specific C240 M5 configuration, not either M5HD SAS adapter |
The Bottom Line
Buy or retain UCSC-SAS-M5HD when your software stack needs individual disks. Replace it with the Cisco-supported UCSC-RAID-M5HD when the C240 M5 SX must create hardware RAID virtual disks. Verify the chassis, cabling, firmware and HUU procedure before changing controllers.
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