NETGEAR is aware of a growing number of phone and online scams. To learn how to stay safe click here.
Forum Discussion
Solved
RN314 and high ATA error count on 2 disks
I have a RN314 and I've got high ATA error counts. I have two RAID 1 volumes, each 2x3TB disks. One disk in each volume has been reporting increasing ATA counts. Disk: Detected increasing ATA e...
UNCs and Reallocated Sectors definitely point to the disk. ATA errors relate to the SATA bus, so can either be an issue with the NAS or the disk.
I did run one of the blocks of errors through ChatGPT and it quite helpfully gave me the following, which seems plausible and was interested to read that it deems the problem to be media rather than cable/controller...
[Wed Apr 16 13:46:51 2025] do_marvell_9170_recover: ignoring PCI device (8086:3a22) at PCI#0
This is referencing a PCI device (likely a storage controller), specifically one with a Marvell 9170 chip.
It's being ignored during recovery, which probably means it's not the active controller for the affected drive or it's not directly involved in the failure.
🧨 [Wed Apr 16 13:46:51 2025] ata4.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
This line indicates the drive experienced an ATA exception, but the error mask (Emask) and other flags are all zeros — suggesting a lower-level issue, possibly at the drive/media level rather than the controller or cable.
⚠️ [Wed Apr 16 13:46:51 2025] ata4.00: irq_stat 0x40000001
A hardware-level status update. The irq_stat suggests that an uncorrectable error (typically media-related) occurred during a DMA operation (direct memory access).
❌ [Wed Apr 16 13:46:51 2025] ata4.00: failed command: READ DMA
The drive failed to read data using the DMA command, which is used for high-speed data transfer without CPU involvement.
📦 cmd c8/00:08:48:00:00/00:00:00:00:00/e0 tag 0 dma 4096 in
This is a low-level command format showing the drive attempted to read 4 KB (4096) from a specific sector (starting at LBA 0x48).
It failed with the result:
res 51/40:00:49:00:00/00:00:00:00:00/e0 Emask 0x9 (media error)Emask 0x9 = media error, which typically means:
The drive tried to read data from a sector, but the data was uncorrectable, likely due to physical degradation of the sector.
🟥 [Wed Apr 16 13:46:51 2025] ata4.00: status: { DRDY ERR }
DRDY = Drive is ready
ERR = An error occurred
→ The drive responded, but the command couldn't be completed successfully.
🧨 [Wed Apr 16 13:46:51 2025] ata4.00: error: { UNC }
UNC = Uncorrectable error — usually a sign the drive couldn't recover the data from that sector even with ECC (error correction code).
⚙️ [Wed Apr 16 13:46:51 2025] ata4.00: configured for UDMA/133
Just confirms the drive is running in UDMA/133 mode — normal for SATA.
âś… [Wed Apr 16 13:46:51 2025] ata4: EH complete
EH = Error Handling
The kernel’s ATA error handler has finished trying to deal with the issue.
UNCs and Reallocated Sectors definitely point to the disk. ATA errors relate to the SATA bus, so can either be an issue with the NAS or the disk.
One bad drive can also sometimes cause ATA errors on another channel.
Your data is definitely at risk, so you need to complete a backup ASAP. If you do really have two failing drives (and I think that's most likely), the second could fail during re-sync of the first replacement, which often results in data loss.
I was copying from vol2 to vol1 and in the evening, disk 4 was removed from the array on vol2, but also now vol1 shows the first disk as status unknown, so that's probably failed too - I did see some disk logs showing the disk test status as failed - odd that it's not recognised as failed and therefore degraded the volume.
Anyway, I have almost got all data from vol2 to 1 and then I'll remove disk 1 and swap disk 3 to disk 1 and vol1 data onto the other disk,
Will I need to clean disk 3 before I put it in as disk 1?
NETGEAR Academy
Boost your skills with the Netgear Academy - Get trained, certified and stay ahead with the latest Netgear technology!
Join Us!
