Extent selection with mapped raid

A system comprising:

• at least one processor;
• and
• a memory comprising code stored thereon that, when executed, performs a method of allocating one or more mapped RAID extents comprising:
• determining a pool of N physical storage devices;
• selecting M physical storage portions, wherein each of the M physical storage portions is selected from a different one of the N physical storage devices of the pool, wherein said selecting is performed in accordance with a neighborhood matrix denoting a distribution of neighboring physical storage portions across the N physical storage devices of the pool;
• and
• allocating a first mapped RAID extent as the selected M physical storage portions, wherein the first mapped RAID extent denotes a stripe of a RAID group.

A computer readable medium comprising code stored thereon that, when executed, performs a method of allocating one or more mapped RAID extents comprising:

• determining a pool of N physical storage devices;
• selecting M physical storage portions, wherein each of the M physical storage portions is selected from a different one of the N physical storage devices of the pool, wherein said selecting is performed in accordance with a neighborhood matrix denoting a distribution of neighboring physical storage portions across the N physical storage devices of the pool;
• and
• allocating a first mapped RAID extent as the selected M physical storage portions, wherein the first mapped RAID extent denotes a stripe of a RAID group.