How do I change the OS block size

Question

I am using SUSE 11SP3 and formatted the devices with a block size of 4KB using mkfs.ext3. /sys/block/sda/queue/logical_block_size and /sys/block/sda/queue/physical_block_size show the OS is using 512 bytes.

1. How can I change the OS block size to match the 4KB FS block size?
2. I created a RAID0 array form the disks. Do I need to change the block size of the RAID array and the disks it is comprised of or should I only change the RAID0 array?

Answer 1

You cant change the physical_block_size and logical_block_size because they are values which the hard disk control expose to your kernel. You can use dumpe2fs to get the file system block size. For the right array setup take a look at: https://wiki.archlinux.org/index.php/RAID#Format_the_RAID_Filesystem