Shingled magnetic recording
Shingled Magnetic Recording (SMR) is a magnetic storage data recording technology for HDD that allows up to 30% higher capacity by overlapping the previous drive tracks. Thus, the tracks partially overlap, similar to roof shingles. The overlapping tracks slow down random write performance since the operating system must perform a read modify write of the entire zone. SAS SMR drives use the Zoned Block Command (ZBC) set. SATA SMR drives use the Zoned ATA Command (ZAC) set.
|
Drives |
Host Managed (HM) |
Host Aware (HA) | Device Managed (DM) |
|---|---|---|---|
| SAS SMR | HBA Only (ZBC) | HBA Only (ZBC) | Not supported |
| SATA SMR | HBA Only (ZAC) | HBA Only (ZAC) | SATA SMR + DM is not supported |
This method has the following benefits:
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Support for HDD with higher storage density
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Supports for HDD with lower cost per GB
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Support for HDD with lower power per GB