SMR – Shingled Magnetic Recording – a disk and tape drive data recording technology. With disk drive shingling, write tracks are partially overlapped, leaving narrower read tracks, as a way of increasing capacity per platter. The write tracks are grouped in blocks separated by inter-block spaces. Re-writing data is a sequential process involving track erasing and writing within a block, which slows down the write process compared to non-shingled drives.

SMR graphic.

The SMR access process can be handled by the host application (host-managed SMR) or by the drive itself (drive-managed SMR.)

LTO tapes also use shingled tracks.