I've had a rash of file system access issues recently where files become inaccessible, usually resolved by a restart or messing around. I have a pair of Samsung SSD 970 EVO Plus 1TBs mirrored as my cache pool in ZFS (recently switched from BTRFS to experiment with). Other than installing ZFS Master, I have not configured automatic snapshots or any other additional setup for ZFS specifically. Diagnostics and smart reports attached. I presume it's a hardware issue, but I'm unsure on exact next steps to troubleshoot/triage. Perhaps remove one of the cache drives. Errors in ZFS pool root@UNRAID:/mnt/user/Scratch# zpool status -v
pool: cache
state: ONLINE
status: One or more devices has experienced an error resulting in data
corruption. Applications may be affected.
action: Restore the file in question if possible. Otherwise restore the
entire pool from backup.
see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-8A
scan: scrub repaired 0B in 00:09:21 with 16 errors on Mon Feb 2 11:03:53 2026
config:
NAME STATE READ WRITE CKSUM
cache ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
nvme1n1p1 ONLINE 0 0 27.1K
nvme0n1p1 ONLINE 0 0 27.1K
errors: Permanent errors have been detected in the following files:
/mnt/cache/Scratch/vm/isos/haos_ova-13.2.qcow2
/mnt/cache/Scratch/docker/duplicacy/bin/duplicacy_linux_x64_3.2.5
/mnt/cache/Scratch/docker/containers/overlay2/89b8086d04d95fd0f21f9937170ae437b3287cd9bdaef19a60ba7728d7d339ed/diff/app/radarr/bin/Radarr.Core.pdb
/mnt/cache/Scratch/docker/containers/overlay2/59fc7b9bf7f256b860a21f55c080c242ede729a1426482d8e250b2ed86678ee4/diff/app/sonarr/bin/Sonarr.Core.pdb
/mnt/cache/Scratch/docker/containers/overlay2/8e7e76832d6dc8145f04dcbaf143fb7fa07bbf092a861d7f2e7d2cb1d95daab1/diff/lib/ld-musl-x86_64.so.1
/mnt/cache/Scratch/docker/containers/overlay2/1e6272eee2a99e4e6e1c44367080fad9cdbc4e85e15a2b03d274f222e2cef33a/diff/ffmpeg/lib/libavformat.so.59
/mnt/cache/Scratch/docker/containers/overlay2/567a58c5ce269d7b47c3a2fb6feeefa5439f5967713a6d7e2b70ff7ecbb60f24/diff/usr/local/bin/duplicacy_web
/mnt/cache/Scratch/docker/containers/overlay2/1d414267a5606678ba2e5e1b07b9f90758de45e4af5cf35414add951a77a8658/diff/usr/local/bin/gosu
/mnt/cache/Scratch/docker/profilarr/db/.git/objects/pack/pack-18d9e5ff64883fdd7223068fa2c8356d0866cd90.pack
/mnt/cache/Scratch/docker/containers/overlay2/aaa312ab84c321ccb41621197c069613bfc182270621dd1864e5f053ae6a4b04/diff/app/prowlarr/bin/System.Private.Xml.dll
/mnt/cache/Scratch/docker/containers/overlay2/89b8086d04d95fd0f21f9937170ae437b3287cd9bdaef19a60ba7728d7d339ed/diff/app/radarr/bin/System.Private.CoreLib.dllCache 1 Smart smartctl 7.5 2025-04-30 r5714 [x86_64-linux-6.12.54-Unraid] (local build)
Copyright (C) 2002-25, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Number: Samsung SSD 970 EVO Plus 1TB
Serial Number: S59ANM0R546074E
Firmware Version: 2B2QEXM7
PCI Vendor/Subsystem ID: 0x144d
IEEE OUI Identifier: 0x002538
Total NVM Capacity: 1,000,204,886,016 [1.00 TB]
Unallocated NVM Capacity: 0
Controller ID: 4
NVMe Version: 1.3
Number of Namespaces: 1
Namespace 1 Size/Capacity: 1,000,204,886,016 [1.00 TB]
Namespace 1 Utilization: 544,146,423,808 [544 GB]
Namespace 1 Formatted LBA Size: 512
Namespace 1 IEEE EUI-64: 002538 551191b229
Local Time is: Mon Feb 2 13:14:22 2026 EST
Firmware Updates (0x16): 3 Slots, no Reset required
Optional Admin Commands (0x0017): Security Format Frmw_DL Self_Test
Optional NVM Commands (0x005f): Comp Wr_Unc DS_Mngmt Wr_Zero Sav/Sel_Feat Timestmp
Log Page Attributes (0x03): S/H_per_NS Cmd_Eff_Lg
Maximum Data Transfer Size: 512 Pages
Warning Comp. Temp. Threshold: 85 Celsius
Critical Comp. Temp. Threshold: 85 Celsius
Supported Power States
St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat
0 + 7.80W - - 0 0 0 0 0 0
1 + 6.00W - - 1 1 1 1 0 0
2 + 3.40W - - 2 2 2 2 0 0
3 - 0.0700W - - 3 3 3 3 210 1200
4 - 0.0100W - - 4 4 4 4 2000 8000
Supported LBA Sizes (NSID 0x1)
Id Fmt Data Metadt Rel_Perf
0 + 512 0 0
=== START OF SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
SMART/Health Information (NVMe Log 0x02, NSID 0xffffffff)
Critical Warning: 0x00
Temperature: 46 Celsius
Available Spare: 100%
Available Spare Threshold: 10%
Percentage Used: 22%
Data Units Read: 298,745,209 [152 TB]
Data Units Written: 843,580,978 [431 TB]
Host Read Commands: 1,829,510,180
Host Write Commands: 6,662,348,226
Controller Busy Time: 45,227
Power Cycles: 53
Power On Hours: 26,285
Unsafe Shutdowns: 16
Media and Data Integrity Errors: 0
Error Information Log Entries: 159
Warning Comp. Temperature Time: 0
Critical Comp. Temperature Time: 0
Temperature Sensor 1: 46 Celsius
Temperature Sensor 2: 60 Celsius
Error Information (NVMe Log 0x01, 16 of 64 entries)
Num ErrCount SQId CmdId Status PELoc LBA NSID VS Message
0 159 0 0x0018 0x4004 - 0 0 - Invalid Field in Command
Self-test Log (NVMe Log 0x06, NSID 0xffffffff)
Self-test status: No self-test in progress
Num Test_Description Status Power_on_Hours Failing_LBA NSID Seg SCT Code
0 Extended Completed without error 26285 - - - - -
Cache 2 Smart smartctl 7.5 2025-04-30 r5714 [x86_64-linux-6.12.54-Unraid] (local build)
Copyright (C) 2002-25, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Number: Samsung SSD 970 EVO Plus 1TB
Serial Number: S4P4NF0M600551L
Firmware Version: 2B2QEXM7
PCI Vendor/Subsystem ID: 0x144d
IEEE OUI Identifier: 0x002538
Total NVM Capacity: 1,000,204,886,016 [1.00 TB]
Unallocated NVM Capacity: 0
Controller ID: 4
NVMe Version: 1.3
Number of Namespaces: 1
Namespace 1 Size/Capacity: 1,000,204,886,016 [1.00 TB]
Namespace 1 Utilization: 544,159,617,024 [544 GB]
Namespace 1 Formatted LBA Size: 512
Namespace 1 IEEE EUI-64: 002538 5691b3268d
Local Time is: Mon Feb 2 13:14:33 2026 EST
Firmware Updates (0x16): 3 Slots, no Reset required
Optional Admin Commands (0x0017): Security Format Frmw_DL Self_Test
Optional NVM Commands (0x005f): Comp Wr_Unc DS_Mngmt Wr_Zero Sav/Sel_Feat Timestmp
Log Page Attributes (0x03): S/H_per_NS Cmd_Eff_Lg
Maximum Data Transfer Size: 512 Pages
Warning Comp. Temp. Threshold: 85 Celsius
Critical Comp. Temp. Threshold: 85 Celsius
Supported Power States
St Op Max Active Idle RL RT WL WT Ent_Lat Ex_Lat
0 + 7.80W - - 0 0 0 0 0 0
1 + 6.00W - - 1 1 1 1 0 0
2 + 3.40W - - 2 2 2 2 0 0
3 - 0.0700W - - 3 3 3 3 210 1200
4 - 0.0100W - - 4 4 4 4 2000 8000
Supported LBA Sizes (NSID 0x1)
Id Fmt Data Metadt Rel_Perf
0 + 512 0 0
=== START OF SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
SMART/Health Information (NVMe Log 0x02, NSID 0xffffffff)
Critical Warning: 0x00
Temperature: 38 Celsius
Available Spare: 100%
Available Spare Threshold: 10%
Percentage Used: 22%
Data Units Read: 332,652,519 [170 TB]
Data Units Written: 837,685,747 [428 TB]
Host Read Commands: 1,982,650,828
Host Write Commands: 6,638,082,258
Controller Busy Time: 42,500
Power Cycles: 49
Power On Hours: 25,973
Unsafe Shutdowns: 16
Media and Data Integrity Errors: 0
Error Information Log Entries: 149
Warning Comp. Temperature Time: 0
Critical Comp. Temperature Time: 0
Temperature Sensor 1: 38 Celsius
Temperature Sensor 2: 41 Celsius
Error Information (NVMe Log 0x01, 16 of 64 entries)
Num ErrCount SQId CmdId Status PELoc LBA NSID VS Message
0 149 0 0x0008 0x4004 - 0 0 - Invalid Field in Command
Self-test Log (NVMe Log 0x06, NSID 0xffffffff)
Self-test status: No self-test in progress
Num Test_Description Status Power_on_Hours Failing_LBA NSID Seg SCT Code
0 Extended Completed without error 25972 - - - - -
unraid-diagnostics-20260202-1107.zip unraid-smart-20260202-1314-cache2.zip unraid-smart-20260202-1313-cache1.zip