Hello, I have a few questions about Software RAID and 4k-sector drives. I already searched the web, but some questions are left. 1) (this one is not directly raid-related) I understand, that newer kernels can determine whether a drive uses 4k physical sectors even if it presents 512-byte logical sectors to the outside. (via the sector_size_supported() patch by Matthew Wilcox) Is this only an information given to userland tools, or will the linux kernel change its behavior (e.g. use 4k-blocks for such block devices)? (I guess it's only an information for userland tools.) 2) Will Software RAID work with physical 4k-sector drives... - that simulate logical 512 byte sectors? - that also have logical 4k-sectors? (I'm pretty sure, the answer to both questions is yes.) 3) Will Software RAID work in mixed setups? i.e.: what combinations of the following drive types are possible? - 512b physical / 512b logical - 4k physical / 512b logical - 4k physical / 4k logical And: Will the resulting md block device have 512 byte blocks or 4k blocks? (I would guess that you need to have the same logical sector size for all disks.) I am aware of the performance problems due to read-modify-write cycles and potential misalignment. This has been discussed in plenty of articles on the web. It would be great if someone could clear things up a little (and tell me if me guesses are correct). Thanks, Florian -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
