When we create LVMs or the RAID partitions, the data we save in the parition is divided into PEs or the chunks respectively instead of the conventional blocks of ext3 or ext4.
My doubt is whose responsibility (RAM, Processor, OS) it is to divide the data into PEs or chunks such that the data would be stored on the harddisk in that format.
Moreover is it possible to change the default PE or chunk size? If so, how and when generally we get the requirement of changing the size?
My understanding on LVM PE is as follows: The PE size in LVM is 4MB. Generally a sector is 512 bytes on the hard disk. And on formatting a partition with LVM, each file saved in that partition by default takes 4MB minimum space and continuous sectors and though if any free space is left over in that 4MB it will not allow another file to fit in the same space. The new file again has to go for the new PE. Similar the case with RAID chunks.
Please correct me if I have understood wrongly.