Nearline SAS
Nearline SAS or NL-SAS drives are enterprise SATA drives with a SAS interface, head, media, and rotational speed of traditional enterprise-class SATA drives with the fully capable SAS interface typical for classic SAS drives. System and storage vendors like Dell, EMC, Fujitsu, and IBM are offering these disks for SAN arrays, NAS solutions, and server systems.
They feature the following benefits compared to SATA:
- Dual ports allowing redundant paths
- Ability to connect a device to multiple computers
- Full SCSI command set
- Faster interface compared to SATA, up to 20%, no STP (Serial ATA Tunneling Protocol) overhead
- No need for SATA interposer cards (for high availability of SATA drives SATA interposer cards are needed)
To summarize: Nearline SAS drives are simply big, cheap, and slow SAS drives targeted toward nearline storage.
Read more about this topic: Serial Attached SCSI