My question is about the minimum data block size (cluster, number of sectors) that the OS use to communicate with the hard drive using ATA commands?
I know that the physical sector size is 512 Bytes AND
new hard drive have 4096 Bytes (4K) AND
the OS allocation unit (aka cluster) equals to 1 or more sectors.
Is the cluster size depend on the file system or the OS?
assuming the cluster size is (4096 Bytes, 8 physical sector) ==> Is it always enforced with ATA commands? that is, if an application issued an ATA READ SECTOR command to read 1 sector, does the OS enforce cluster size and request 8 sectors or request 1 sector?
Is the number of sectors or clusters that the OS reserve for files always even number or could be odd number?