I have been given the following disk recommendation:
The disk drives should have standard native sector sizes of 512 bytes and 4 KB. Hard disks with sector sizes larger than 4 KB may cause errors when attempting to store application data.
The allocation unit size must be configured to 64K when formatting the disk.
What is the difference between allocation unit size and sector size?
The allocation unit size is a term of the file system (operating system software) , the sector size is a term of the underlying hardware.
File systems do not necessarily use single sectors to manage drive space. Sometimes they combine single physical sectors into a logical administration unit. The size of such a bunch of sectors is called "allocation unit size".
When formating a partition you typically have the choice to set the "allocation unit size" (cluster size in Microsoft operating systems).
A common combination in the NTFS (Microsoft file system, used in Windows operating systems) is to combine 8 sectors with a size of 512 byte into a so-called "cluster". Cluster seems to be the Microsoft equivalent of the more generalized term "allocation unit size". This cluster size of 4096 byte is the minimum increment/decrement when occupying/releasing storage space.
