Server Hard Drives - SAS & SATA Enterprise

SAS or SATA: what your controller supports

A SAS drive needs a SAS controller, and a SATA drive runs on either kind: per Seagate's support note, SAS controllers accept SATA drives, while SATA controllers cannot run SAS drives.

Our SAS vs SATA guide compares the two interfaces on speed, reliability and compatibility.

2.5-inch or 3.5-inch: set by the drive bays

The server's drive bays fix the form factor: Dell's R740 and R740xd technical guide shows the same R740xd in a 24 x 2.5-inch and a 12 x 3.5-inch front-drive configuration. A 2.5-inch drive can still go in a 3.5-inch bay, because Dell's R740 manual describes installing a 2.5-inch drive into a 3.5-inch drive adapter that then fits the 3.5-inch drive carrier. Carriers are under hard drive caddies and trays.

Spindle speed and what each class is for

The 15K and 10K RPM classes are SAS performance drives, capped at 900GB and 2.4TB per drive in Seagate's enterprise range, and the 7.2K RPM class, sold as NL-SAS or SATA, is where the high capacities live; the 15K, 10K and NL-SAS pages cover each class.

New, recertified, refurbished or used: what the terms mean

The condition term tells you who checked a drive and who stands behind it:

Mixing drives in one RAID array

Keep each virtual disk to one interface and one drive technology; spindle speeds and link rates can differ. Dell's PERC 11 user guide sets these rules:

When a member fails, Dell asks for a replacement of the same protocol and technology with equal or greater capacity. Our RAID calculator estimates usable capacity for each RAID level.

RAID levels and backplanes

Drives join an array through the server's RAID controller: see RAID controllers, our guide to choosing RAID 5, RAID 6 or RAID 10 for picking a level, and our R740 and R740xd backplane guide for PowerEdge drive-bay options.

Refurbished server hard drive questions

Are refurbished server hard drives reliable?

A refurbished enterprise drive is as dependable as the checks behind it. Enterasource tests every server hard drive when it reaches our lab and again before dispatch, then covers it with an Enterasource warranty; each listing states the term. Run any drive, new or refurbished, in a redundant RAID level with a spare on hand: protection against a drive failure comes from the array.

What is the difference between refurbished and recertified drives?

Recertified drives went back through the original maker's own program. Seagate describes its recertified drives as used, reconditioned or repurposed units that are tested, sanitized and certified to its factory standards, and Western Digital certifies its recertified products to WD quality standards, each under the maker's terms. A refurbished drive from Enterasource is a pre-owned enterprise drive tested in our own lab and covered by our warranty.

Can I mix drive sizes or speeds in one RAID array?

Speeds, yes; interfaces and drive technologies, no. Dell's PERC 11 user guide supports mixing 7,200, 10,000 and 15,000 RPM drives, and 3, 6 and 12Gbps drives, when they share an interface and technology, but never mixes SAS and SATA, or spinning drives and SSDs, in one virtual disk. For sizes, Dell asks for a replacement of equal or greater capacity than the drive it replaces.

Looking for solid-state storage? Browse enterprise SSDs for NVMe, SAS and SATA options, or configure a complete server.