From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Ni Subject: Re: Can't reshape raid0 to raid10 Date: Thu, 5 Feb 2015 03:44:10 -0500 (EST) Message-ID: <724950041.5158431.1423125850171.JavaMail.zimbra@redhat.com> References: <1718053393.1731733.1419906625563.JavaMail.zimbra@redhat.com> <484995116.1735572.1419909221275.JavaMail.zimbra@redhat.com> <20150204173921.23df9d79@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20150204173921.23df9d79@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: NeilBrown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids ----- Original Message ----- > From: "NeilBrown" > To: "Xiao Ni" > Cc: linux-raid@vger.kernel.org > Sent: Wednesday, February 4, 2015 2:39:21 PM > Subject: Re: Can't reshape raid0 to raid10 >=20 > On Mon, 29 Dec 2014 22:13:41 -0500 (EST) Xiao Ni wro= te: >=20 > > Hi Neil > >=20 > > When I try to reshape a raid0 to raid10, it'll fail like this: > >=20 > > [root@dhcp-12-133 mdadm-3.3.2]# lsblk > > NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT > > sda 8:0 0 111.8G 0 disk > > =E2=94=9C=E2=94=80sda1 8:1 0 1000M 0 part /= boot > > =E2=94=9C=E2=94=80sda2 8:2 0 29.3G 0 part / > > =E2=94=9C=E2=94=80sda3 8:3 0 512M 0 part [= SWAP] > > =E2=94=9C=E2=94=80sda4 8:4 0 1K 0 part > > =E2=94=9C=E2=94=80sda5 8:5 0 102M 0 part > > =E2=94=94=E2=94=80sda6 8:6 0 10.1G 0 part > > =E2=94=94=E2=94=80VolGroup00-LogVol00 254:0 0 9.9G 0 lvm > > sdb 8:16 0 111.8G 0 disk > > =E2=94=9C=E2=94=80sdb1 8:17 0 2G 0 part > > =E2=94=94=E2=94=80sdb2 8:18 0 10G 0 part > > sdc 8:32 0 186.3G 0 disk > > =E2=94=9C=E2=94=80sdc1 8:33 0 2G 0 part > > =E2=94=94=E2=94=80sdc2 8:34 0 10G 0 part > > sdd 8:48 0 111.8G 0 disk > > =E2=94=9C=E2=94=80sdd1 8:49 0 2G 0 part > > =E2=94=94=E2=94=80sdd2 8:50 0 10G 0 part > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm -CR /dev/md0 -l0 -n3 /dev/sdb= 1 > > /dev/sdc1 /dev/sdd1 > > mdadm: Defaulting to version 1.2 metadata > > mdadm: array /dev/md0 started. > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm --grow /dev/md0 -l10 -a /dev/= sdb2 > > /dev/sdc2 /dev/sdd2 > > mdadm: level of /dev/md0 changed to raid10 > > mdadm: add new device failed for /dev/sdb2 as 6: No space left on d= evice > >=20 > > =20 > > But if I reshape the raid0 to raid5, reshape raid5 to raid0, the= n > > reshape raid0 to raid10 use > > the same command it'll succeed. > >=20 > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm -CR /dev/md0 -l0 -n3 /dev/sdb= 1 > > /dev/sdc1 /dev/sdd1 > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm --grow /dev/md0 -l5 > > [root@dhcp-12-133 mdadm-3.3.2]# cat /proc/mdstat > > Personalities : [raid6] [raid5] [raid4] [raid0] [raid10] > > md0 : active raid5 sdd1[2] sdc1[1] sdb1[0] > > 6285312 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/= 3] > > [UUU_] > > =20 > > unused devices: > >=20 > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm --grow /dev/md0 -l0 > > [root@dhcp-12-133 mdadm-3.3.2]# cat /proc/mdstat > > Personalities : [raid6] [raid5] [raid4] [raid0] [raid10] > > md0 : active raid0 sdd1[2] sdc1[1] sdb1[0] > > 6285312 blocks super 1.2 512k chunks > > =20 > > unused devices: > > [root@dhcp-12-133 mdadm-3.3.2]# mdadm --grow /dev/md0 -l10 -a /dev/= sdb2 > > /dev/sdc2 /dev/sdd2 > > mdadm: level of /dev/md0 changed to raid10 > > mdadm: added /dev/sdb2 > > mdadm: added /dev/sdc2 > > mdadm: added /dev/sdd2 > >=20 > > So I guess it's the problem add the disk to raid10 after the re= shaping. > > In the function > > super_1_validate, it'll set the mddev->dev_sectors using the super= block > > read from disks. > > If it's raid0, the le64_to_cpu(sb-size) is 0. So when add disk to r= aid10 > > bind_rdev_to_array > > return -ENOSPC. > >=20 > > When create raid0, it doesn't write give the value to s->size. = So the > > sb-size is 0. > > I modify the code about Create.c. I'm not sure whether it's right t= o do so. > > But it can resolve > > the problem. >=20 > Thanks for the report. >=20 > I think this need to be fixing in the md driver, when the reshape hap= pens. >=20 > Something like the following. >=20 > NeilBrown >=20 > diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c > index d1203cddb024..b8d76b1fba64 100644 > --- a/drivers/md/raid10.c > +++ b/drivers/md/raid10.c > @@ -3872,7 +3872,7 @@ static int raid10_resize(struct mddev *mddev, s= ector_t > sectors) > return 0; > } > =20 > -static void *raid10_takeover_raid0(struct mddev *mddev) > +static void *raid10_takeover_raid0(struct mddev *mddev, sector_t siz= e, int > devs) > { > struct md_rdev *rdev; > struct r10conf *conf; > @@ -3882,6 +3882,7 @@ static void *raid10_takeover_raid0(struct mddev= *mddev) > mdname(mddev)); > return ERR_PTR(-EINVAL); > } > + sector_div(size, devs); > =20 > /* Set new parameters */ > mddev->new_level =3D 10; > @@ -3892,12 +3893,15 @@ static void *raid10_takeover_raid0(struct mdd= ev > *mddev) > mddev->raid_disks *=3D 2; > /* make sure it will be not marked as dirty */ > mddev->recovery_cp =3D MaxSector; > + mddev->dev_sectors =3D size; > =20 > conf =3D setup_conf(mddev); > if (!IS_ERR(conf)) { > rdev_for_each(rdev, mddev) > - if (rdev->raid_disk >=3D 0) > + if (rdev->raid_disk >=3D 0) { > rdev->new_raid_disk =3D rdev->raid_disk * 2; > + rdev->sectors =3D size; > + } > conf->barrier =3D 1; > } > =20 > @@ -3920,7 +3924,9 @@ static void *raid10_takeover(struct mddev *mdde= v) > mdname(mddev)); > return ERR_PTR(-EINVAL); > } > - return raid10_takeover_raid0(mddev); > + return raid10_takeover_raid0(mddev, > + raid0_conf->strip_zone->zone_end, > + raid0_conf->strip_zone->nb_dev); > } > return ERR_PTR(-EINVAL); > } >=20 Thanks, the problem is fixed. Best Regards Xiao -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html