> md0 : active raid6 sda4[0] sdc4[5] sdd4[4] sdb4[6] > 613409536 blocks super 1.1 level 6, 64k chunk, algorithm 2 [4/4] [UUUU] Why would you use a 4 disk raid6? If 50% of raw capacity is enough just go with raid10. The default 64KiB chunk size has always been very slow for me, try something larger, perhaps even 1MiB. > While rsyncing a file from an ext3 filesystem to a jfs filesystem, rsync isn't really a good diagnostic, how's performance with something simple, dd, bonnie++, whatever? > I looked at stripe_cache_size and increased it to 384 Much too low, I usually set it to 8192. Take care you don't run out of RAM, though, it's in pages/disk (16KiB in your case). > blockdev --getra reports 256 for all involved raid components. In my experience only the top component of a layered block device matters at all, that would be the LV. 256 sectors / 128 KiB seems awfully low, try something higher, 2MiB at least. > Am I crazy? Is 12.5MB/s (average) what I should expect, here? No, it's probably just that the default tunining options are not very good. Cheers, C. -- 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
