On Tue, May 06, 2014 at 09:02:46AM +0200, john terragon wrote: > just one last doubt: > > why do you use --align-payload=1024? (or 8912) > Cryptsetup man says that the default for the payload alignment is 2048 > (512-byte sectors). So, it's already aligned by default to 4K-byte > physical sectors (if that was your concern). Am I missing something?
With 4K sectors, I agree that 2048 would be better. What I was trying to do there is avoid write amplification. After reading http://wiki.drewhess.com/wiki/Creating_an_encrypted_filesystem_on_a_partition I went with mdadm --create /dev/md8 --level=5 --raid-devices=5 /dev/sd[abdef]1 --chunk=256 --bitmap=/boot/bitmap-md8 which I believe required me to use cryptsetup luksFormat --align-payload=1024 -s 256 -c aes-xts-plain64 /dev/md8 (that was with 5 drives, or 4 drives with data). Would agree with the math? If so, for 4K sector sizes, if we have to use align-payload=1024, in turn I'd have to use --chunk=512. Does that sound right? Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/ | PGP 1024R/763BE901 -- 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
