The partition.config file lets you manage your cache space more efficiently by creating cache partitions of different sizes. You can further configure these partitions to store data from certain origin servers and domains in the
hosting.config file. This allows you to take better advantage of caching of frequently visited sites where the content changes infrequently.
partition_number is a number between 1 and 255 (the maximum number of partitions is 255).
partition_size is the amount of cache space allocated to the partition. This value can be either a percentage of the total cache space or an absolute value. The absolute value must be a multiple of 128 MB, where 128 MB is the smallest value. If you specify a percentage, the size is rounded down to the closest multiple of 128 MB. Each partition is striped across several disks to achieve parallel I/O. For example, if there are four disks, a 1 GB partition will have 256 MB on each disk (assuming each disk has enough free space available).