On 6/23/14, Martin K. Petersen <martin.peter...@oracle.com> wrote: > Anyway. The short answer is that Linux will pretty much always do I/O in > multiples of the system page size regardless of the logical block size > of the underlying device. There are a few exceptions to this such as > direct I/O, legacy filesystems using bufferheads and raw block device > access.
Thanks for the clarification. And some random notes: Note that gdisk gives default 8 sector alignment value for AF disks. That is 'sector' meant by gdisk is 'Logical Sector'! Sufficiently determined user may create misaligned partitions by playing with alignment value and partition start/end values. There are SSDs with 4K, 8K block/page sizes and 512K, 1M, 1.5M Erase block sizes. Partitions should be aligned with Erase blocks. And filesystem block size (leafsize for btrfs. Default 16 K) should be in multiples of device block size. Regards, Imran -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
