▲ 2 r/UgreenNASync
Can't add drive - sdb2 does not have a valid v1.2 superblock
Hi,
I'm trying to replace my 2nd drive with a bigger one (that was, years ago, installed in another RAID). I added the drive and wanted to use it to repair my degraded RAID1. But after asking for the password to format the drive it just says "failed".
If I look into /var/log/kern.log I get this:
md: sdb2 does not have a valid v1.2 superblock, not importing!
md: md_import_device returned -22
After googling, I found this might be because it was part of another RAID before. I tried deleting all partitions using fdisk, executing wipefs -a /dev/sdb and executing mdadm --zero-superblock /dev/sdb but that didn't help.
I also tried creating a new drive pool, adding it as a basic volume and formatting it, which worked just fine.
I then removed the volume and drive pool again and tried to repair my existing RAID and still get the same error.
Any ideas?
Full log:
2026-05-14T17:04:07.069520+02:00 DXP2800-F839 kernel: [ 1438.709862] sdb:
2026-05-14T17:04:07.181503+02:00 DXP2800-F839 kernel: [ 1438.821674] sdb: sdb1
2026-05-14T17:04:07.329479+02:00 DXP2800-F839 kernel: [ 1438.970259] sdb: sdb1 sdb2
2026-05-14T17:04:07.513474+02:00 DXP2800-F839 kernel: [ 1439.152539] md: sdb2 does not have a valid v1.2 superblock, not importing!
2026-05-14T17:04:07.513499+02:00 DXP2800-F839 kernel: [ 1439.152557] md: md_import_device returned -22
^C
root@DXP2800-F839:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
loop0 7:0 0 755.1M 0 loop /rootfs/base
loop1 7:1 0 76.5M 0 loop /rootfs/kernel
loop2 7:2 0 77.1M 0 loop /rootfs/apt
loop3 7:3 0 168.2M 0 loop /rootfs/fw
loop4 7:4 0 4K 0 loop /rootfs/oem
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 15.3G 0 part
└─sda2 8:2 0 916.3G 0 part
└─md1 9:1 0 916.1G 0 raid1
└─ug_E2CE32_1778750304_pool1-volume1 253:0 0 916.1G 0 lvm /volume1
sdb 8:16 0 2.7T 0 disk
├─sdb1 8:17 0 15.3G 0 part
└─sdb2 8:18 0 2.7T 0 part
mmcblk0 179:0 0 29.2G 0 disk
├─mmcblk0p1 179:1 0 256M 0 part /boot
├─mmcblk0p2 179:2 0 2G 0 part
├─mmcblk0p3 179:3 0 10M 0 part /mnt/factory
├─mmcblk0p4 179:4 0 2G 0 part /rootfs
├─mmcblk0p5 179:5 0 2G 0 part [SWAP]
├─mmcblk0p6 179:6 0 4G 0 part /ugreen
├─mmcblk0p7 179:7 0 18.9G 0 part /overlay
└─mmcblk0p128 179:128 0 239K 0 part
zram0 252:0 0 961M 0 disk [SWAP]
zram1 252:1 0 961M 0 disk [SWAP]
zram2 252:2 0 961M 0 disk [SWAP]
zram3 252:3 0 961M 0 disk [SWAP]
mmcblk0boot0 179:256 0 4M 1 disk
mmcblk0boot1 179:512 0 4M 1 disk
root@DXP2800-F839:~# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.38.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): d
Partition number (1,2, default 2): 2
Partition 2 has been deleted.
Command (m for help): d
Selected partition 1
Partition 1 has been deleted.
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
root@DXP2800-F839:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
loop0 7:0 0 755.1M 0 loop /rootfs/base
loop1 7:1 0 76.5M 0 loop /rootfs/kernel
loop2 7:2 0 77.1M 0 loop /rootfs/apt
loop3 7:3 0 168.2M 0 loop /rootfs/fw
loop4 7:4 0 4K 0 loop /rootfs/oem
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 15.3G 0 part
└─sda2 8:2 0 916.3G 0 part
└─md1 9:1 0 916.1G 0 raid1
└─ug_E2CE32_1778750304_pool1-volume1 253:0 0 916.1G 0 lvm /volume1
sdb 8:16 0 2.7T 0 disk
mmcblk0 179:0 0 29.2G 0 disk
├─mmcblk0p1 179:1 0 256M 0 part /boot
├─mmcblk0p2 179:2 0 2G 0 part
├─mmcblk0p3 179:3 0 10M 0 part /mnt/factory
├─mmcblk0p4 179:4 0 2G 0 part /rootfs
├─mmcblk0p5 179:5 0 2G 0 part [SWAP]
├─mmcblk0p6 179:6 0 4G 0 part /ugreen
├─mmcblk0p7 179:7 0 18.9G 0 part /overlay
└─mmcblk0p128 179:128 0 239K 0 part
zram0 252:0 0 961M 0 disk [SWAP]
zram1 252:1 0 961M 0 disk [SWAP]
zram2 252:2 0 961M 0 disk [SWAP]
zram3 252:3 0 961M 0 disk [SWAP]
mmcblk0boot0 179:256 0 4M 1 disk
mmcblk0boot1 179:512 0 4M 1 disk
root@DXP2800-F839:~# wipefs -a /dev/sdb
/dev/sdb: 8 bytes were erased at offset 0x00000200 (gpt): 45 46 49 20 50 41 52 54
/dev/sdb: 8 bytes were erased at offset 0x2baa1475e00 (gpt): 45 46 49 20 50 41 52 54
/dev/sdb: 2 bytes were erased at offset 0x000001fe (PMBR): 55 aa
/dev/sdb: calling ioctl to re-read partition table: Success
root@DXP2800-F839:~# mdadm --zero-superblock /dev/sdb
mdadm: Unrecognised md component device - /dev/sdb
root@DXP2800-F839:~# tail -f /var/log/kern.log
2026-05-14T17:00:30.841545+02:00 DXP2800-F839 kernel: [ 1222.475501] md: md_import_device returned -22
2026-05-14T17:02:34.221503+02:00 DXP2800-F839 kernel: [ 1345.860420] sdb: sdb1 sdb2
2026-05-14T17:03:24.201479+02:00 DXP2800-F839 kernel: [ 1395.839644] sdb:
2026-05-14T17:04:06.909673+02:00 DXP2800-F839 kernel: [ 1438.549606] sdb:
2026-05-14T17:04:07.069520+02:00 DXP2800-F839 kernel: [ 1438.709862] sdb:
2026-05-14T17:04:07.181503+02:00 DXP2800-F839 kernel: [ 1438.821674] sdb: sdb1
2026-05-14T17:04:07.329479+02:00 DXP2800-F839 kernel: [ 1438.970259] sdb: sdb1 sdb2
2026-05-14T17:04:07.513474+02:00 DXP2800-F839 kernel: [ 1439.152539] md: sdb2 does not have a valid v1.2 superblock, not importing!
2026-05-14T17:04:07.513499+02:00 DXP2800-F839 kernel: [ 1439.152557] md: md_import_device returned -22
2026-05-14T17:37:27.517486+02:00 DXP2800-F839 kernel: [ 3439.204297] sdb:
2026-05-14T17:39:01.409478+02:00 DXP2800-F839 kernel: [ 3533.097087] sdb:
2026-05-14T17:39:01.541537+02:00 DXP2800-F839 kernel: [ 3533.229688] sdb: sdb1
2026-05-14T17:39:01.645534+02:00 DXP2800-F839 kernel: [ 3533.333435] sdb: sdb1 sdb2
2026-05-14T17:39:07.313503+02:00 DXP2800-F839 kernel: [ 3539.000016] md: sdb2 does not have a valid v1.2 superblock, not importing!
2026-05-14T17:39:07.313520+02:00 DXP2800-F839 kernel: [ 3539.000034] md: md_import_device returned -22
u/Hot_Succotash4676 — 9 days ago