Hi Wol, This indeed fixed the problem. What I did for the record and for any newbie reading this post: # Regrow the RAID1 to 5 devices (this fixed the weird removed messages) sudo mdadm /dev/md9 --grow --raid-devices=5 # Make 3 disks faulty sudo mdadm /dev/md9 --fail /dev/sdc9 sudo mdadm /dev/md9 --fail /dev/sdd9 sudo mdadm /dev/md9 --fail /dev/sde9 # Remove 3 disks sudo mdadm /dev/md9 --remove /dev/sdc9 sudo mdadm /dev/md9 --remove /dev/sdd9 sudo mdadm /dev/md9 --remove /dev/sde9 # Reduce the number of devices in RAID1 sudo mdadm /dev/md9 --grow --raid-devices=2 # Re-attach the 3 disks (they become spare) sudo mdadm /dev/md9 --add /dev/sdc9 sudo mdadm /dev/md9 --add /dev/sdd9 sudo mdadm /dev/md9 --add /dev/sde9 # Change the level of raid sudo mdadm /dev/md9 --grow --level=5 --raid-devices=5 # Then wait about 24h for the raid to reshape! ------------------------- Santiago DIEZ Quark Systems & CAOBA 23 rue du Buisson Saint-Louis, 75010 Paris ------------------------- On Wed, Nov 15, 2017 at 6:14 PM, Wols Lists <antlists@xxxxxxxxxxxxxxx> wrote: > > On 15/11/17 16:52, Santiago DIEZ wrote: > > Hi, > > > > I started by mistake a raid as RAID1 with 5 disks when my desire was > > to start it as RAID5. Technically, there is no data at all so I could > > entirely recreate the raid but this is NOT what I want. I'm taking > > this opportunity as an exercise to change a raid level. > > > > The initial state of the raid is: > > md9 : active raid1 sda9[0] sdb9[1] sdc9[2] sdd9[3] sde9[4] > > 5846755328 blocks super 1.2 [5/5] [UUUUU] > > bitmap: 0/44 pages [0KB], 65536KB chunk > > > > # I tried to change the level with: > > mdadm /dev/md9 --grow --level=5 > > # But got the error : > > mdadm: Impossibly level change request for RAID1 > > I'll leave the rest for someone else (or maybe me later :-) but just to > explain the "impossible level change", you cannot change a mirror with > more than two active devices. You need to have two active, three spares, > before it will change. > > Cheers, > Wol -- 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
