On Sat, 19 Feb 2011 12:13:08 +0100 Albert Pauw <albert.pauw@xxxxxxxxx> wrote: > I have dabbed a bit with the standard raid1/raid5 sets and am just > diving into this whole ddf container stuff, > and see how I can fail, remove and add a disk. > > Here is what I have, Fedora 14, five 1GB Sata disks (they are virtual > disks under VirtualBox but it all seems > to work well under the standard raid stuff. For mdadm I am using the > latest git version, with version nr 3.1.4. > > I created a ddf container: > > mdadm -C /dev/md/container -e ddf -l container -n 5 /dev/sd[b-f] > > I now create a raid 5 set in this container: > > mdadm -C /dev/md1 -l raid5 -n 5 /dev/md/container > > This all seems to work, I also noticed that after a stop and start of > both the container and the raidset, > the container has been renamed to /dev/md/ddf0 which points to /dev/md127. That depends a bit on how you restart it. The ddf metadata doesn't store a name for the array so if mdadm has to assign a name it uses /dev/md/ddfNNN for some NNN. If you list the array in /etc/mdadm.conf with the name you want, then mdadm has a better chance of using that name. > > I now fail one disk in the raidset: > > mdadm -f /dev/md1 /dev/sdc > > I noticed that it is removed from the md1 raidset, and marked > online,failed in the container. So far so > good. When I now stop the md1 array and start it again, it will be back > again with all 5 disks, clean, no failure This is not good. I have created a fix and added it to my git tree: the 'master' branch of git://neil.brown.name/mdadm > although in the container the disk is marked failed. I then remove it > from the container: > > mdadm -r /dev/md127 /dev/sdc > > I clean the disk with mdadm --zero-superblock /dev/sdc and add it again. > > But how do I add this disk again to the md1 raidset? It should get added automatically. 'mdmon' runs in the background, notices this sort of thing. I just experimented and it didn't quite work as I expected. I'll have a closer look next week. > > I see in the container that /dev/sdc is back, with status > "active/Online, Failed" and a new disk is added > with no device file and status "Global-Spare/Online". > > I am confused now. > > So my question: how do I replace a faulty disk in a raidset, which is in > a ddf container? You don't. You just make sure the container has enough spares and mdmon will sort things out ... or it will once I find and fix the bug. > > Thanks and bare with me, I am relatively new to all this. > Thanks for experimenting an reporting. NeilBrown -- 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
