Dynamic guarding of a storage media

A fixed data region on a storage medium may be allocated with one of a variety of allocation schemes (e.g., a randomly writable allocation scheme, a non-randomly writeable allocation scheme with a first data isolator spacing, a non-randomly writeable allocation scheme with a second data isolator spacing, and a non-randomly writeable allocation scheme with no dynamic isolators). Dynamic sub-region spacing refers at least to the number of data tracks in a data region of a magnetic disc between dynamic isolators and the number of bits in a data region in flash memory between dynamic isolators. The presently disclosed technology adapts isolators on the storage medium to create dynamic sub-regions based on characteristics of the storage medium, characteristics of the data, and/or expected access patterns of data to be written to the storage medium.