Server drives come with three interfaces: SATA, SAS and NVMe. The interface decides which RAID controller can manage the drive, how fast the link is and which drives can share an array. This guide lists what the Dell PERC and HPE Smart Array / MR user guides say about each interface, which controller families support which drives, and the mixing rules you must follow when you build or repair arrays.
Before you start
- Identify the exact controller model in iDRAC, iLO or the server's configuration; support differs between models of the same family.
- Check that the server's drive backplane matches the interface you plan to use. The server's own user guide and specification sheet list supported backplanes.
- Plan one interface type per array.
The three interfaces as the vendor guides describe them
| Interface | Speeds listed | Notes from the guides |
|---|---|---|
| SATA | 3 Gbps and 6 Gbps | Supported on every PERC 11 and PERC 12 model except the external H965e and the NVMe-only cards |
| SAS | 6, 12 and 22.5 Gbps (SAS4, "24G") | Dell: 22.5 Gbps is the data rate and 24 Gbps the link speed, and the terms are used synonymously |
| NVMe (PCIe) | Gen3 (8 GT/s), Gen4 (16 GT/s), Gen5 (32 GT/s) | PERC 11 runs NVMe drives at up to x2 lane width; Gen5 is listed only for the PERC H975i Front |
Which controllers handle which drives
| Controller | SATA | SAS | NVMe |
|---|---|---|---|
| Dell PERC H755 adapter, H755 MX | Yes | Yes (12 Gbps) | Yes (Gen3, Gen4) |
| Dell PERC H755 front SAS, H750 adapter SAS, H355, H350 | Yes | Yes (12 Gbps) | No |
| Dell PERC H755N front NVMe | No | No | Yes (Gen3, Gen4) |
| Dell PERC H965i adapter, front, MX and H365i | Yes | Yes (up to 22.5 Gbps) | Yes (Gen3, Gen4) |
| Dell PERC H965e adapter (external) | No | Yes | No |
| Dell PERC H975i Front | No | No | Yes (Gen3, Gen4, Gen5) |
| HPE Smart Array S100i SR Gen10 (software RAID) | Yes | No | No |
| HPE Smart Array E-class and P-class SR Gen10 | Yes (6G) | Yes (12G) | No |
| HPE SR Gen10 Plus 400/900 series (SR416i-a, SR932i-p) | Yes (6G) | Yes (24G) | Yes (16G, U.2 and U.3) |
| HPE SR Gen11 400/900 series | Yes (6G) | Yes (24G) | Yes (16G, U.3) |
| HPE MR Gen11 (MR216i, MR408i, MR416i) | Yes (6 Gbps) | Yes (12 Gbps) | Yes (16 Gbps) |
HPE calls the MR Gen11 family "tri-mode" controllers because one controller handles all three interfaces. Boot devices are separate again: Dell BOSS cards and HPE NS204i use M.2 drives (see boot-optimized drives).
Mixing rules inside an array
- Dell PERC 11: mixing NVMe drives with SAS and SATA is not supported. Different speeds and link rates of the same type (SAS or SATA) and technology (HDD or SSD) can be mixed.
- Dell PERC 12/13: mixing NVMe with SAS or SATA drives under one controller at the same time is not supported, although direct-attached NVMe drives can coexist with PERC-managed SAS/SATA drives in the same server. A replacement drive must use the same protocol as the existing drives: SAS for SAS, SATA for SATA. Dell states that cross-protocol replacement is not supported.
- HPE Smart Array: the SSA CLI guide states that mixed drives are not allowed on the same array or logical drive. When several drive types exist and you select all drives, you must give the
drivetypeparameter (for examplesas,sata,ss_sasorss_sata). - HPE MR Gen11: replacement and original drives must be the same interface type, such as SAS or SATA. The logical-drive wizard filters drives by interface: SAS, SATA, NVMe or All.
Warning: A drive of the wrong interface will not join a degraded array, and on Dell PERC a drive inserted into a slot that belongs to a redundant virtual disk can start a rebuild that overwrites whatever is on it. Never insert a drive holding data you need into a configured slot. Back up first.
Sector sizes
Drives also differ in logical sector size. Dell's PERC 11 and PERC 12 guides allow mixing 512-byte native and 512-byte emulated (512e) drives in one virtual disk, but not 512-byte and 4 KB native (4Kn) drives. On PERC 11, 4K drives are supported only in UEFI mode, and PERC 12 storage boot is UEFI-only. HPE MR Gen11 lets you filter drives by logical sector size (512 B, 4 KB or Both) when you create a logical drive.
Hot-plug support
- The PERC 12 specification tables list hot-swap devices as supported on the H965, H975 and H365 series.
- HPE describes the SR Gen11 controllers as attaching to internal hot-plug drives, and the S100i software RAID as supporting hot-plug and non-hot-plug SATA drives.
- Hot-plug also depends on the server's backplane and drive carriers, so confirm in the server's user guide before removing a drive from a running system.
NVMe notes
- PERC 12 and 13 controllers support only single-namespace NVMe devices; multi-namespace devices are not supported.
- Dell's PERC 11 guide explains that NVMe drives have no World Wide Name, so tools build one from drive information that may not match the label on the drive. Use the bay number or locate LED to identify the drive.
- HPE MR controllers are managed with HPE MR Storage Administrator or StorCLI, not with Smart Storage Administrator. See HPE MR Gen11 RAID.
Frequently asked questions
Can I replace a failed SAS drive with a SATA drive?
No. Dell does not support cross-protocol replacement, and HPE requires the replacement to be the same type as the failed drive.
Do I need a tri-mode controller for NVMe RAID?
You need a controller that lists NVMe support: on Dell, for example the PERC H755N, H755 adapter, H965 series or H975i; on HPE, the SR Gen10 Plus, SR Gen11 or MR Gen11 families. Older HPE SR Gen10 E-class and P-class controllers list SAS and SATA only.
Checklist
- Controller model confirmed and its supported interfaces checked.
- One interface (and one media type) per array.
- No NVMe mixed with SAS/SATA on one PERC controller.
- No 4Kn drives in the same virtual disk as 512n/512e drives.
- Replacements match protocol and capacity; slots checked before inserting used drives.
- Hot-plug confirmed for the server's backplane before removing drives live.
Skyline can supply, configure and maintain Dell, HPE and Huawei servers under an annual maintenance contract (AMC). Contact us.
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