Dynamic hybrid shingled magnetic recording device

A method for operating a Data Storage Device (DSD) including a disk for storing data, the method comprising:

• receiving a write command to write data in a Conventional Magnetic Recording (CMR) realm to be formatted for writing data in non-overlapping tracks, wherein the disk includes a plurality of areas of the disk that can be formatted as a CMR realm or as a Shingled Magnetic Recording (SMR) realm formatted for writing data in overlapping tracks;
• determining whether performance of the write command would require writing to begin in a portion of the CMR realm that has not been written with non-overlapping tracks;
• in response to determining that the performance of the write command would require writing to begin in a portion of the CMR realm that has not been written with non-overlapping tracks, writing a predefined data pattern using non-overlapping tracks in the portion of the CMR realm that has not been written with non-overlapping tracks;
• and
• in response to determining that the performance of the write command would not require writing to begin in a portion of the CMR realm that has not been written with non-overlapping tracks, writing the data for the write command without writing the predefined data pattern using non-overlapping tracks.

A non-transitory computer readable storage medium storing computer-executable instructions for operating a Data Storage Device (DSD) including a disk for storing data, wherein when the computer-executable instructions are executed by a controller of the DSD, the computer-executable instructions cause the controller to:

• receive a write command to write data in a Conventional Magnetic Recording (CMR) realm that has not been completely formatted for CMR, wherein the disk includes a plurality of areas of the disk that can be formatted as a CMR realm for writing data in non-overlapping tracks or as a Shingled Magnetic Recording (SMR) realm formatted for writing data in overlapping tracks;
• determine whether performance of the write command would require writing to begin in a portion of the CMR realm that has not been written with non-overlapping tracks;
• and
• in response to determining that the performance of the write command would require writing to begin in a portion of the CMR realm that has not been written with non-overlapping tracks, write a predefined data pattern adjacent a location corresponding to where the data is to be written for the write command.