Hardwareinfo: TrueNAS version: TrueNAS SCALE 24.10.2.4 / Electric Eel
- Motherboard: ASRock Rack X470D4U2-2T
- CPU: AMD Ryzen 5 3600X
- Boot device: SK hynix 32GB M.2 SATA SSD
-
currently appears as
/dev/sde -
serial:
ES67N110810507P9W
-
- Main pool:
TheBig-
6 x 12TB HDD
-
RAIDZ2
-
mix of Seagate IronWolf / Exos-class drives
-
- NVMe pool:
NVME-
1 x ~2TB NVMe SSD
-
serial:
21376D801551
-
TrueNAS SCALE 24.10.2.4 / Electric Eel
I’m looking for guidance before running any repair/replacement commands.
I have a 6 x 12TB RAIDZ2 pool named TheBig. It was healthy before reboot. No drive replacements, no reinstall, no intentional pool changes, and I do not believe I upgraded immediately before this happened.
This happened when I rebooted to try to reset Plex. I had put the NAS behind a VPN on my router, but undid that because it caused connection issues with plex.
After reboot, the pool/datasets disappeared from the GUI. TrueNAS showed disks with exported pools. I did not create a new pool or add disks.
Initial command-line import showed both pools as available and ONLINE:
/sbin/zpool import
pool: TheBig
id: 10158275043973833898
state: ONLINE
config:
TheBig ONLINE
raidz2-0 ONLINE
sdd2 ONLINE
sdg2 ONLINE
sdc2 ONLINE
sda2 ONLINE
11ddf7f4-94bb-4cae-ac82-45d585a69710 ONLINE
sdb2 ONLINE
pool: NVME
id: 9608143190421123067
state: ONLINE
config:
NVME ONLINE
e30a35c1-48d9-45fc-809d-3aa1112b3119 ONLINE
Manual import succeeded, but datasets failed to mount because ZFS tried to mount the pool roots at /TheBig and /NVME instead of /mnt/TheBig and /mnt/NVME:
/sbin/zpool import NVME
cannot mount '/NVME': failed to create mountpoint: Read-only file system
Import was successful, but unable to mount some datasets
/sbin/zpool import TheBig
cannot mount '/TheBig': failed to create mountpoint: Read-only file system
Import was successful, but unable to mount some datasets
zfs get mountpoint showed:
NAME PROPERTY VALUE SOURCE
TheBig mountpoint /TheBig default
NAME PROPERTY VALUE SOURCE
NVME mountpoint /NVME default
TrueNAS middleware, however, reported the pools as ONLINE with paths under /mnt:
midclt call pool.query
TheBig:
"path": "/mnt/TheBig"
"status": "ONLINE"
NVME:
"path": "/mnt/NVME"
"status": "ONLINE"
I rebooted again. After that, TheBig came up DEGRADED.
Current zpool status -P:
pool: TheBig
state: DEGRADED
status: One or more devices could not be used because the label is missing or
invalid. Sufficient replicas exist for the pool to continue
functioning in a degraded state.
action: Replace the device using 'zpool replace'.
config:
NAME STATE READ WRITE CKSUM
TheBig DEGRADED 0 0 0
raidz2-0 DEGRADED 0 0 0
17554408218717640207 FAULTED 0 0 0 was /dev/sdd2
/dev/sdg2 ONLINE 0 0 0
11710781531430353535 REMOVED 0 0 0 was /dev/sdc2
/dev/sda2 ONLINE 0 0 0
/dev/disk/by-partuuid/11ddf7f4-94bb-4cae-ac82-45d585a69710 ONLINE 0 0 0
/dev/sdb2 ONLINE 0 0 0
errors: No known data errors
The part that confuses me is that the supposedly missing GUIDs still appear readable from attached disks.
zdb -l /dev/sdf2 | grep "guid:" shows:
pool_guid: 10158275043973833898
top_guid: 2887469638244621148
guid: 17554408218717640207
That is the same GUID currently reported as FAULTED:
17554408218717640207 FAULTED was /dev/sdd2
Also, zdb -l /dev/sdd2 shows a valid ZFS label for the same pool and reports:
pool_guid: 10158275043973833898
top_guid: 2887469638244621148
guid: 11710781531430353535
That is the GUID currently reported as REMOVED:
11710781531430353535 REMOVED was /dev/sdc2
lsblk -o NAME,SIZE,SERIAL currently shows:
NAME SIZE SERIAL
sda 10.9T ZHZ0F25X
├─sda1 2G
└─sda2 10.9T
sdb 10.9T ZHZ05Z4H
├─sdb1 2G
└─sdb2 10.9T
sdc 10.9T ZTN00AWM
└─sdc1 10.9T
sdd 10.9T ZHZ463HS
├─sdd1 2G
└─sdd2 10.9T
sde 29.8G ES67N110810507P9W
├─sde1 260M
└─sde2 29.6G
sdf 10.9T ZHZ5RWM2
├─sdf1 2G
└─sdf2 10.9T
sdg 10.9T ZHZ5X5FW
├─sdg1 2G
└─sdg2 10.9T
nvme0n1 1.8T 21376D801551
└─nvme0n1p1 1.8T
One oddity: /dev/sdc has only one large ZFS partition, while the other pool disks mostly have a 2G swap partition plus a ZFS partition.
sgdisk -p /dev/sdc:
Disk /dev/sdc: 23437770752 sectors, 10.9 TiB
Model: ST12000NE0008-2P
Disk identifier (GUID): 4E273AC5-190C-4647-9F0B-9C4A4B3F1EBF
Number Start (sector) End (sector) Size Code Name
1 2048 23437768703 10.9 TiB BF01 data
blkid /dev/sdc*:
/dev/sdc1: LABEL="TheBig" UUID="10158275043973833898" UUID_SUB="8444992749518646930" BLOCK_SIZE="4096" TYPE="zfs_member" PARTLABEL="data" PARTUUID="11ddf7f4-94bb-4cae-ac82-45d585a69710"
sgdisk -p /dev/sdd:
Disk /dev/sdd: 23437770752 sectors, 10.9 TiB
Model: ST12000VN0008-2J
Disk identifier (GUID): 3D4AB86B-661D-11EA-92C3-D05099D5BDEA
Number Start (sector) End (sector) Size Code Name
1 128 4194431 2.0 GiB A502
2 4194432 23437770711 10.9 TiB A504
blkid /dev/sdd*:
/dev/sdd1: LABEL="freenas:swap0" TYPE="linux_raid_member"
/dev/sdd2: LABEL="TheBig" UUID="10158275043973833898" UUID_SUB="11710781531430353535" BLOCK_SIZE="4096" TYPE="zfs_member" PARTUUID="3da59291-661d-11ea-92c3-d05099d5bdea"
Relevant /dev/disk/by-partuuid links:
11ddf7f4-94bb-4cae-ac82-45d585a69710 -> ../../sdc1
3da59291-661d-11ea-92c3-d05099d5bdea -> ../../sdd2
SMART short attributes on the drives I checked are clean:
Reallocated_Sector_Ct 0
Current_Pending_Sector 0
Offline_Uncorrectable 0
for:
/dev/sdc
/dev/sdf
/dev/sdd
zpool history TheBig | tail -50 shows no recent replace/remove/detach operations. The last relevant entry appears to be:
2026-06-01.16:17:21 zpool import TheBig
I also tried:
sudo /sbin/zpool import -d /dev/disk/by-id TheBig
but it returned:
cannot import 'TheBig': a pool with that name already exists
use the form 'zpool import <pool | id> <newpool>' to give it a new name
and:
sudo /sbin/zpool import -d /dev/disk/by-id
returned:
no pools available to import
because the pool is already imported, though degraded.
Question:
What is the safest recovery path here?
I have not run zpool replace, zpool clear, zpool detach, wiped labels, or repartitioned anything.
Given that the vdev GUIDs reported as FAULTED/REMOVED appear to still be readable via zdb -l from attached disks, and SMART looks clean, I’m trying to understand whether this is a device mapping / stale import / label issue rather than actual disk failure.
I want to avoid making the situation worse by replacing or clearing the wrong device.
I’ll be looking through the other topics here… Thanks for any help. additional hardware info below:
DDR4_A1
Kingston
Product Name
DIMM
Product Part Number
9965745-041.A00G
Product Serial Number
9416BD90
Product Extra
2666 MT/s 32GB
DDR4_A2
Product Manufacturer Name
Kingston
Product Name
DIMM
Product Part Number
9965745-002.A00G
Product Serial Number
205C0E53
Product Extra
2666 MT/s 16GB
DDR4_B1
Product Manufacturer Name
Kingston
Product Name
DIMM
Product Part Number
9965745-022.A00G
Product Serial Number
4A6E24ED
Product Extra
2666 MT/s 32GB
DDR4_B2
Product Manufacturer Name
Kingston
Product Name
DIMM
Product Part Number
9965745-002.A00G
255C0B95
Product Extra
2666 MT/s 16GB
Storage (SATA3_0)
Product Part Number
ST12000VN0008-2JH101
ZHZ05Z4H
Storage (SATA3_1)
ST12000VN0008-2JH101
ZHZ0F25X
Storage (SATA3_2)
ST12000NE0008-2PK103
ZTN00AWM
Storage (SATA3_3)
ST12000VN0008-2JH101
ZHZ463HS
Storage (SATA3_4)
ST12000NE0008-2JL101
ZHZ5RWM2
Storage (SATA3_5)
ST12000NE0008-2JL101
ZHZ5X5FW
Storage (M2_1(PCIE))
WDC WDS200T2B0C-00PXH0
21376D801551
Storage (M2_2(SATA))
SK hynix SC215 M.2 2242 32GB
ES67N110810507P9W