> Simply restricting larger-LBS disks is inflexible. In some scenarios, > only disks with 512 LBS are available currently, but later, disks with > 4k LBS may be added to the array. Having to have the foresight to preemptively configure a larger logical block size at creation time also seems somewhat inflexible :) In general I am not a big fan of mixing devices with different properties. I have regretted stacking the logical block size on several occasions. I am also concerned about PI breaking if the logical block size facing upwards does not match the actual logical block size of the component devices below. In theory it should work with the PI interval exponent but it is something that needs to be tested. What if the MD device's configured logical block size is larger than the physical block size of the underlying devices? Then we'll end up reporting a logical block size larger than the physical block size. Ugh. Oh, and what about atomics? -- Martin K. Petersen
