I was working on recovering a damaged array today, and I used mdadm 3.1.2 with --assume-clean to get it up and running. I was surprised when I wasn't able to mount the filesystem on the array after starting it, so I did a closer comparison of a dump of the original array configuration vs. the new one. I found that the main difference was that the component size was 1KB smaller now than it used to be. The array was originally created with mdadm 2.6.8. So I compiled the old 2.6.8 version of mdadm and used the same mdadm --assume-clean command, and bingo, the component size matched the original array config and it mounted just fine. So, I suspect there is some new code in mdadm 3.1 that wasn't in 2.6.x to try to make I/O 4KB-aligned on non-aligned partitions. Is that accurate? If so, is there a way to tell mdadm to behave like older mdadm versions in these cases? -Justin -- 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
