Hi Neil
When I try to reshape a raid0 to raid10, it'll fail like this:
[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
├─sda1 8:1 0 1000M 0 part /boot
├─sda2 8:2 0 29.3G 0 part /
├─sda3 8:3 0 512M 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
├─sda5 8:5 0 102M 0 part
└─sda6 8:6 0 10.1G 0 part
└─VolGroup00-LogVol00 254:0 0 9.9G 0 lvm
sdb 8:16 0 111.8G 0 disk
├─sdb1 8:17 0 2G 0 part
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 186.3G 0 disk
├─sdc1 8:33 0 2G 0 part
└─sdc2 8:34 0 10G 0 part
sdd 8:48 0 111.8G 0 disk
├─sdd1 8:49 0 2G 0 part
└─sdd2 8:50 0 10G 0 part
[root@dhcp-12-133 mdadm-3.3.2]# mdadm -CR /dev/md0 -l0 -n3 /dev/sdb1 /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 device
But if I reshape the raid0 to raid5, reshape raid5 to raid0, then reshape raid0 to raid10 use
the same command it'll succeed.
[root@dhcp-12-133 mdadm-3.3.2]# mdadm -CR /dev/md0 -l0 -n3 /dev/sdb1 /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_]
unused devices: <none>
[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
unused devices: <none>
[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
So I guess it's the problem add the disk to raid10 after the reshaping. In the function
super_1_validate, it'll set the mddev->dev_sectors using the superblock read from disks.
If it's raid0, the le64_to_cpu(sb-size) is 0. So when add disk to raid10 bind_rdev_to_array
return -ENOSPC.
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 to do so. But it can resolve
the problem.
diff --git a/Create.c b/Create.c
index 330c5b4..f3135c5 100644
--- a/Create.c
+++ b/Create.c
@@ -489,7 +489,7 @@ int Create(struct supertype *st, char *mddev,
pr_err("no size and no drives given - aborting create.\n");
return 1;
}
- if (s->level > 0 || s->level == LEVEL_MULTIPATH
+ if (s->level >= 0 || s->level == LEVEL_MULTIPATH
|| s->level == LEVEL_FAULTY
|| st->ss->external ) {
/* size is meaningful */
--To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html