Hi Martin, On Sat, Sep 14, 2013 at 4:16 PM, Martin Wilck <mwilck@xxxxxxxx> wrote: > Hi Francis, hi Neil, > >> Still testing MD arrays using DDF metadata and find another possible issues :) >> >> I'm creating a new DDF array containing 2 disks. After that >> /proc/mdstat looks correct: >> >> # cat /proc/mdstat >> Personalities : [raid1] >> md124 : active raid1 loop0[1] loop1[0] >> 84416 blocks super external:/md125/0 [2/2] [UU] >> >> md125 : inactive loop1[1](S) loop0[0](S) >> 65536 blocks super external:ddf >> >> Now I'm stopping the array and restart it by incrementaly adding the 2 disks: >> # mdadm --stop /dev/md124 >> # mdadm --stop /dev/md125 >> # mdadm -IRs /dev/loop0 > > This is wrong, because -IRs "wills can the mapfile for arrays that are > being incrementally assembled snd will try to start any that are not > already started". > > mdadm -IRs will first add /dev/loop0, then see that there is an > incomplete array, and start it. > >> # mdadm -IRs /dev/loop1 > > Now you add /dev/loop1, but as the array is already started, it will be > added as a spare. That's what you see below. Ah you're right, sorry for the noise, however I still doesn't understand my last point, please see the end of the email. > > However, there is room for improvement here. The array hasn't been > written to, so even if it is started, it should be possible to re-add > the second disk cleanly. > > Looking into that. > thanks > Martin > > >> # cat /proc/mdstat >> Personalities : [raid1] >> md124 : active (auto-read-only) raid1 loop1[2] loop0[0] >> 84416 blocks super external:/md125/0 [2/1] [_U] >> >> md125 : inactive loop1[1](S) loop0[0](S) >> 65536 blocks super external:ddf >> >> Parsing mdstat content tells me disk "loop1" have a role number equal >> to 2 which is greater than 1 indicating that "loop1" is a spare disk >> and the "[_U]" below indicates "loop1" is down". >> >> Why is "loop1" down now ? >> >> I decided to still use the md device by creating a new partition on it: >> # fdisk /dev/md124 >> ... >> Calling ioctl() to re-read partition table. >> Syncing disks. >> >> Now inspecting /proc/mdstat: >> >> # cat /proc/mdstat >> Personalities : [raid1] >> md124 : active raid1 loop1[2] loop0[0] >> 84416 blocks super external:/md125/0 [2/2] [UU] >> >> md125 : inactive loop1[1](S) loop0[0](S) >> 65536 blocks super external:ddf >> >> which looks even weirder: "loop1[2]" indicates that the disk is a >> spare one whereas "[UU]" tells me the opposite. >> >> Could you tell me if I'm wrong in my interpretation or what's going wrong ? What about the loop1 in spare and [UU] indicating that loop1 is used ? Thanks -- Francis -- 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
