>>>>> "Andy" == Andy Grover <agrover@xxxxxxxxxx> writes: Andy> Yes, don't you need FORMAT UNIT because protection information is Andy> going to mean the pi-enabled lun will need to report less blocks? Modern disk drives won't shrink when you reformat them with PI. This is a result of an IDEMA agreement about LBA counts. And if you create a 10GB PI LUN on an array you'll get 10GB for data. Andy> The ramdisk backstore changes in this series allocate extra space Andy> for PI info, but my understanding was that especially for Andy> emulation with block and fileio backstores, everything needs to go Andy> in the same amount of space. For both file and block I'd recommend we store the PI in a separate block device or file unless the backing device is PI-capable. Andy> Furthermore, if we want PI info stored along with the blocks, then Andy> block and fileio backstore formats are no longer going to be 1:1 Andy> -- requiring offset calculations, non-aligned read-modify-write, Andy> and all that unpleasantness to be handled? I only think interleaved makes sense if you're passing the PI through instead of emulating. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
