Shingled magnetic Recording

Improving data space on any storage device is a huge challenge for both, users and the developers or manufacturers of the electronic device. The newly introduced technique has brought about a drastic change in the technology world. These are mostly employed in hard disks and the way in which data is organized on it. This technology development was introduced with the idea of improving the amount of storage on the disk.

Data is stored in tracks and sectors on the disc. In a normally operating hard disk we see that data is written parallel to each other on data tracks which are closely grouped. This method of operation is termed Perpendicular magnetic recording.

On the other hand, we come across Shingled magnetic recording (SMR), where a small amount of data is overwritten on data tracks, i.e. by overlapping each other. This makes the current track narrower and thus increasing the storage capacity.

Read/Write heads play a major role in recording and retrieving information in any hard disk. In Shingled magnetic way of recording information, the write head is wider compared to the reading heads which gives us a greater chance to store data. There are couple of ways in which this is operated.

Firstly, it is managed by the drive itself. There, we have the firmware that controls the operation and the way in which it stores the data. Then we have a Host managed technique where the software or operating system is responsible to provide information how data is to be read and in which order it has to be written. A Helium filled hard drive is an example that uses this technique. Finally we have the Host aware technique which is a combination of both.

There are certain criteria that needs to be taken into consideration when using SMR over PMR (Perpendicular magnetic recording). In SMR, there lies a huge challenge to see that not all the data is overwritten. SMR increases magnetization effect which is good but the process of writing is slow as it needs to take extra care that data is not damaged by overwriting.

Ever since the introduction of this technique, we can see a gradual rise in sales of hard drives. We need to ensure that or data is always backed up and there is no replacement for this.