Applicable Products
- QNAP NAS
- QNAP Expansion Enclosure (if applicable)
Overview
This FAQ is intended for advanced users who want to perform an initial classification and analysis of disk drop issues by reviewing messages and keywords in the Event Log and Kernel Log.
The results described in this FAQ indicate only a Possible Cause or Investigation Direction. They do not represent a confirmed Root Cause.
The same Event Message or Kernel Message can be caused by different factors, such as the disk, disk tray, disk bay, SATA link, backplane, controller, or other system factors. Therefore, a failed component should not be identified based on a single keyword alone.
Important: Kernel Log keywords in this FAQ are intended only to help classify an issue and identify possible investigation directions. A single message or keyword cannot confirm which component has failed. Final Root Cause and hardware failure determination should be based on QNAP Technical Support's analysis of the complete Diagnostic Logs and system status.
Safety: If the RAID is already degraded and another RAID member disk is also abnormal, or if multiple disks in the same RAID group are experiencing issues, protect the data first. Do not remove, swap, or move disks, or perform tests that may increase data risk merely to verify a log-based assumption.
Quick Log Analysis Reference
| Category |
Event / Kernel Message or Keyword |
What It May Indicate |
Possible Cause / Investigation Direction |
| Link failed |
Failed to access the installed drive / reset failed, giving up |
SATA link reset/recovery failed and the system ultimately could not access the disk |
Disk / SATA Link / Controller / Connection Path |
| Unrecoverable error |
Medium error / Unrecovered read error / UNC |
An unrecoverable read error occurred on the disk |
Disk Media / Bad Sector / Disk |
| Command timeout |
Command timeout / no response / repeated link reset |
The NAS sent a command to the disk but did not receive a response within the expected time |
Disk / SATA Controller / Connection / Software |
| Hardware failure |
Host: Disk X: Disconnected / ATA bus error |
An ATA communication-path bus error occurred and may be accompanied by a disconnected disk |
Disk / Slot / SATA Path / Backplane / Controller |
This table is intended only for quick classification. Do not use a single keyword to conclude that a disk, backplane, or controller has failed. Correlate the message with the Disk/Bay mapping, timestamp, Event Log, surrounding Kernel Log messages, and Disk/Bay isolation test results.
Analysis Principle: Do Not Rely on a Single Keyword
When performing advanced disk drop analysis, check the following in sequence:
- Confirm the incident time: Identify the exact timestamp of the disk drop and correlate the Event Log and Kernel Log entries around the same time.
- Identify the disk and bay: Confirm the disk number in the Event Log and correlate it with the ATA/SATA device in the Kernel Log, such as
ata10 or ata22. The mapping between an ATA device and a physical disk bay can vary by NAS model. Do not assume that ataX directly corresponds to the same bay number.
- Identify the error category: Link failed, Unrecoverable error, Command timeout, or Hardware failure.
- Review surrounding messages: Look for related messages such as Disk disconnected, link reset, read error,
UNC, ATA bus error, command timeout, or repeated retry/reset messages.
- Correlate with isolation results: Determine whether the issue follows the disk, whether different disks show the same issue in the same bay, and whether multiple disks report similar errors at approximately the same time.
# Category 1 — Link failed
Typical Messages
Event Message:
Failed to access the installed drive
Kernel Message / Keyword:
reset failed, giving up
Messages around the same event may also include:
hard resetting link
link is slow to respond
SATA link down
reset failed
How should I interpret these messages?
These messages indicate that the system attempted to establish or recover the SATA link to the disk, but the reset/recovery ultimately failed. The disk may therefore become inaccessible or disconnected.
reset failed, giving up does not by itself mean that the disk has definitely failed. The source cases indicate that the disk should be investigated first; if replacing the disk does not resolve the issue, the SATA controller, signal, or another part of the connection path should also be considered.
Possible Cause / Investigation Direction
- Disk
- Disk connection / SATA link
- Disk Tray / connector
- Disk Bay
- Backplane
- SATA Controller / signal path
Correlation
- The issue follows the disk: The possibility of a disk-related issue increases.
- Different disks show the same Link Failure in the same bay: Increase the investigation priority for the Tray / Bay / Backplane / SATA Controller / Signal Path.
- The disk recovers and then fails again: If repeated reset/recovery messages are followed by
reset failed, giving up, analyze the complete communication/link recovery pattern rather than a single reset message.
Category 2 — Unrecoverable error
Typical Messages
Event Messages may include:
Medium error. Run a bad block scan on the drive.
Invalid data found on Host
Medium Error
Unrecovered read error
Kernel Message / Keyword:
UNC
For example:
error: { UNC }
How should I interpret these messages?
UNC, Medium Error, and Unrecovered read error point more directly toward a disk media/read error. In the source case studies, UNC appears together with read errors, Bad Block Scan results, and Disk Health I/O errors.
Possible Cause / Investigation Direction
Disk Media / Bad Sector / Disk
Correlation
Check whether the following are also present:
- SMART abnormality
- Disk Health I/O Error
- Bad Block Scan error
Medium ErrorUnrecovered read errorUNC in the Kernel Log
If several of these findings correlate, the possibility of a disk media/read failure increases. However, a single UNC message should still not be used as the final hardware failure determination.
Category 3 — Command timeout
Event Message
This does not specify a fixed Event Message for this category. Analysis therefore relies primarily on the Kernel Log.
Kernel Log Characteristics
The core condition is that the NAS sent a command to the disk but did not receive a response within the expected time. The source guide describes the timeout condition as no response for more than approximately 30 seconds.
In the case study, a timeout may be followed by messages such as:
hard resetting link
link is slow to respond
resetting link
SATA link down
reset failed, giving up
How should I interpret these messages?
A Command timeout indicates that a disk command did not complete within the expected time, but a timeout alone does not confirm that the disk has failed.
The source guide explicitly lists the following possible directions:
- Disk
- SATA Controller failure
- Software bug
During actual troubleshooting, the connection/link path should also be included in the correlation.
Possible Cause / Investigation Direction
Disk / SATA Controller / Connection Path / Software
Correlation
If you see a sequence similar to:
Command timeout
↓
hard resetting link
↓
link is slow to respond
↓
repeated reset/retry
↓
reset failed, giving up
analyze the complete sequence instead of only the final message.
- The issue follows the disk: The possibility of a disk-related issue increases.
- Different disks experience timeout in the same Bay / Path: Increase the investigation priority for the Bay / Backplane / SATA Controller / Connection Path.
- Multiple disks experience timeout at the same or similar time: Do not immediately conclude that multiple HDDs failed simultaneously. Investigate the Shared Hardware Path / Controller or other system-level factors.
Category 4 — Hardware failure
Typical Messages
Event Message:
Host: Disk X: Disconnected
Kernel Message / Keyword:
ATA bus error
In the source case study, ATA bus error appears repeatedly for the same ATA device and may be accompanied by messages such as:
failed command
hard resetting link
SATA link up
How should I interpret these messages?
ATA bus error indicates an abnormal condition in the ATA communication path. However:
ATA bus error
does not mean:
Backplane is confirmed faulty
This keyword alone also cannot determine whether the failed component is the disk, disk bay, SATA controller, or another component in the path.
Possible Cause / Investigation Direction
- Disk
- Disk connector / Tray
- Disk Bay
- SATA connection path
- Backplane
- SATA Controller
Correlation
- The same disk continues to report ATA bus errors after being moved to another bay: The possibility of a disk-related issue increases.
- Different disks repeatedly report ATA bus errors in the same bay: The possibility of a Bay / Backplane / SATA Path issue increases.
- Similar ATA bus errors occur across multiple bays: Further investigate the Backplane / SATA Controller / Shared connection path.
# How do I correlate the Event Log and Kernel Log?
For example, if the Event Log only shows:
Host: Disk 5: Disconnected
this tells you only that the system observed Disk 5 as disconnected.
If the Kernel Log around the same timestamp also shows:
ata5: ATA bus error
ata5: hard resetting link
you can further focus the investigation on the ATA communication path associated with that disk. However, this still represents only a Possible Cause / Investigation Direction, not a Confirmed Hardware Failure.
Similarly, if the Event Log reports Medium Error, the Kernel Log reports UNC, and Disk Health / Bad Block Scan results are also abnormal, the possibility of a disk media/read error is higher than when any one of these messages appears alone.
Pattern Correlation Reference
| Observed Log Pattern |
Higher-Priority Investigation Direction |
UNC + Medium Error / Unrecovered Read Error |
Disk Media / Bad Sector |
UNC + Disk Health I/O Error + Bad Block Scan Error |
Disk |
reset failed, giving up and the issue follows the disk |
Disk |
reset failed, giving up repeatedly occurs with different disks in the same bay |
Bay / Backplane / SATA Path |
| Command timeout + repeated link reset |
Disk / Connection / SATA Controller |
| Multiple disks report Command timeout at approximately the same time |
Shared Hardware Path / Controller / System-level investigation |
ATA bus error repeatedly occurs in the same bay |
Bay / Backplane / SATA Path |
ATA bus error follows the disk |
Disk |
Disk disconnected + ATA bus error |
ATA communication/path issue; further isolation is required |
| Multiple disks become disconnected at the same time |
Do not assume a single-disk issue; investigate Shared Path / Controller / Backplane / Power / Expansion Path |
"Higher-priority" in this table refers only to troubleshooting priority and does not confirm the Root Cause.
How should I NOT interpret Kernel Logs?
Do not make direct conclusions such as:
UNC = The disk has definitely failed
reset failed = The disk has definitely failed
ATA bus error = The backplane has definitely failed
Command timeout = The controller has definitely failed
A more appropriate analysis flow is:
Keyword
↓
Identify Error Category
↓
Review surrounding Kernel Messages
↓
Correlate Event Log and Timestamp
↓
Identify Disk / Bay / ATA Device
↓
Correlate SMART / Disk Health / Bad Block results
↓
Correlate Disk/Bay Isolation Test
↓
Establish Possible Cause / Investigation Direction
↓
QNAP Technical Support performs final analysis
What information should I provide to QNAP Technical Support?
- NAS Model
- QTS/QuTS hero Firmware Version and Build
- RAID Type / RAID Group Status
- Affected Disk Bay / Slot
- Disk Model / Firmware / Serial Number
- Exact timestamp of the disk drop
- Event Log
- Diagnostic Log ZIP
- SMART / Disk Health Result
- Bad Block Scan Result (if performed)
- Disk/Bay Cross Test Result (if performed)
- Kernel Message / Keyword identified during the initial analysis
- Relevant Kernel Log context before and after the keyword
If you have performed an initial analysis, describe the result as:
Possible investigation direction:
Disk / SATA Link / Backplane / Controller / Media Error / etc.
Avoid describing it as:
Confirmed failed component:
...
unless QNAP Technical Support has completed the analysis and confirmed the result.
Summary
The purpose of advanced Disk Drop Log Analysis is not to identify a failed component from a single Kernel Log keyword. Instead, use the Event Log, Kernel Log, and actual troubleshooting results together to progressively narrow the investigation scope.
The four main categories are:
- Link failed — for example,
reset failed, giving up
- Unrecoverable error — for example,
UNC, Medium Error, Unrecovered read error
- Command timeout — a disk command does not receive a response within the expected time and may be accompanied by repeated link resets
- Hardware failure — for example,
ATA bus error
A keyword provides a Possible Cause / Investigation Direction, not a Confirmed Root Cause.
Final failure analysis and hardware determination should be based on QNAP Technical Support's review of the complete Diagnostic Logs, system status, and isolation test results.
Related Article
适用产品
- QNAP NAS
- QNAP Expansion Enclosure (if applicable)
概述
本常见问题解答适用于希望通过查看事件日志和内核日志中的消息和关键字来进行磁盘掉线问题初步分类和分析的优异用户。
本常见问题解答中描述的结果仅表示可能的原因或调查方向，并不代表已确认的根本原因。
相同的事件消息或内核消息可能由不同因素引起，例如磁盘、磁盘托架、磁盘槽、SATA 链路、背板、控制器或其他系统因素。因此，不应仅根据单个关键字来识别故障组件。
重要提示：本常见问题解答中的内核日志关键字仅用于帮助分类问题和识别可能的调查方向。单个消息或关键字无法确认哪个组件发生故障。较终的根本原因和硬件故障判断应基于 QNAP 技术支持对完整诊断日志和系统状态的分析。
安全提示：如果 RAID 已经降级且另一个 RAID 成员磁盘也异常，或者同一 RAID 组中的多个磁盘出现问题，应首先保护数据。不要仅为了验证基于日志的假设而移除、交换或移动磁盘，或进行可能增加数据风险的测试。
快速日志分析参考
| 类别 |
事件 / 内核消息或关键字 |
可能指示的内容 |
可能的原因 / 调查方向 |
| 链路失败 |
Failed to access the installed drive / reset failed, giving up |
SATA 链路重置 / 恢复失败，系统较终无法访问磁盘 |
磁盘 /SATA 链路 / 控制器 / 连接路径 |
| 不可恢复错误 |
Medium error / Unrecovered read error / UNC |
磁盘上发生了不可恢复的读取错误 |
磁盘介质 / 坏扇区 / 磁盘 |
| 命令超时 |
命令超时 / 无响应 / 重复链路重置 |
NAS 向磁盘发送命令但未在预期时间内收到响应 |
磁盘 /SATA 控制器 / 连接 / 软件 |
| 硬件故障 |
Host: Disk X: Disconnected / ATA bus error |
发生了 ATA 通信路径总线错误，可能伴随有磁盘断开 |
磁盘 / 插槽 / SATA 路径 / 背板 / 控制器 |
此表仅用于快速分类。不要仅凭一个关键词就断定磁盘、背板或控制器已故障。请将信息与磁盘 / 插槽映射、时间戳、事件日志、周围的内核日志消息以及磁盘 / 插槽隔离测试结果进行关联。
分析原则：不要依赖单一关键词
进行优异磁盘掉线分析时，请按顺序检查以下内容：
- 确认事件时间：确定磁盘掉线的更贴合时间戳，并关联同一时间段的事件日志和内核日志条目。
- 识别磁盘和插槽：确认事件日志中的磁盘编号，并将其与内核日志中的 ATA/SATA 设备进行关联，例如
ata10或ata22。ATA 设备与物理磁盘插槽之间的映射可能因 NAS 型号而异。不要假设ataX直接对应相同的插槽编号。
- 识别错误类别：链接失败、不可恢复错误、命令超时或硬件故障。
- 查看周围消息：查找相关消息，如磁盘断开、链接重置、读取错误、
UNC、ATA bus error、命令超时或重复的重试 / 重置消息。
- 与隔离结果关联：确定问题是否跟随磁盘，是否不同磁盘在同一插槽中显示相同问题，以及是否多个磁盘在大致相同时间报告类似错误。
# 类别 1 — 链接失败
典型消息
事件消息：
无法访问已安装的驱动器
内核消息 / 关键词：
重置失败，放弃
同一事件周围的消息可能还包括：
硬重置链接
链接响应缓慢
SATA 链接断开
重置失败
我应该如何解释这些消息？
这些信息表明系统尝试建立或恢复到磁盘的 SATA 连接，但重置 / 恢复较终失败。因此，磁盘可能变得无法访问或断开连接。
reset failed, giving up 本身并不意味着磁盘已经确定故障。源案例表明应首先检查磁盘；如果更换磁盘不能解决问题，还应考虑 SATA 控制器、信号或连接路径的其他部分。
可能原因 / 调查方向
- 磁盘
- 磁盘连接 /SATA 连接
- 磁盘托架 / 连接器
- 磁盘槽
- 背板
- SATA 控制器 / 信号路径
关联
- 问题随磁盘而变化：磁盘相关问题的可能性增加。
- 不同磁盘在同一槽位显示相同的连接失败：增加对托架 / 槽位 / 背板 /SATA 控制器 / 信号路径的调查优先级。
- 磁盘恢复后再次失败：如果重复的重置 / 恢复信息后跟随
reset failed, giving up，应分析完整的通信 / 连接恢复模式，而不是单一的重置信息。
类别 2 — 不可恢复错误
典型信息
事件信息可能包括：
介质错误。对驱动器运行坏块扫描。
主机上发现无效数据
介质错误
未恢复的读取错误
内核信息 / 关键词：
UNC
例如：
错误：{UNC}
我应该如何解释这些信息？
UNC、Medium Error和Unrecovered read error更直接指向磁盘介质 / 读取错误。在源案例研究中，UNC与读取错误、坏块扫描结果和磁盘健康 I / O 错误一起出现。
可能原因 / 调查方向
磁盘介质 / 坏扇区 / 磁盘
关联
检查以下是否也存在：
- SMART 异常
- 磁盘健康 I / O 错误
- 坏块扫描错误
介质错误未恢复的读取错误UNC在内核日志中
如果这些发现中的几个相关联，磁盘介质 / 读取故障的可能性增加。然而，单一的UNC信息仍不应作为较终的硬件故障判断。
类别 3 — 命令超时
事件信息
此类别未指定固定的事件信息。因此，分析主要依赖于内核日志。
内核日志特征
核心情况是 NAS 向磁盘发送了命令，但在预期时间内未收到响应。源指南描述超时情况为超过大约 30 秒没有响应。
在案例研究中，超时后可能会出现如下消息：
硬重置链接
链接响应缓慢
重置链接
SATA 链接断开
重置失败，放弃
我应该如何解释这些消息？
命令超时表示磁盘命令未在预期时间内完成，但仅凭超时无法确认磁盘已故障。
源指南明确列出了以下可能的方向：
在实际故障排除过程中，连接 / 链接路径也应纳入关联分析。
可能原因 / 调查方向
磁盘 /SATA 控制器 / 连接路径 / 软件
关联性
如果您看到类似的序列：
命令超时
↓
硬重置链接
↓
链接响应缓慢
↓
重复重置 / 重试
↓
重置失败，放弃
分析完整的序列而不是仅仅较后一条消息。
- 问题跟随磁盘：磁盘相关问题的可能性增加。
- 不同磁盘在同一插槽 / 路径上超时：提高对插槽 / 背板 /SATA 控制器 / 连接路径的调查优先级。
- 多个磁盘在相同或相似时间超时：不要立即得出多个硬盘同时故障的结论。调查共享硬件路径 / 控制器或其他系统级因素。
类别 4 — 硬件故障
典型消息
事件消息：
主机：磁盘 X：断开连接
内核消息 / 关键词：
ATA 总线错误
在源案例研究中，ATA bus error在同一 ATA 设备上反复出现，可能伴随如下消息：
命令失败
硬重置链接
SATA 链接已连接
我应该如何解读这些信息？
ATA bus error表示 ATA 通信路径中存在异常情况。然而：
ATA 总线错误
并不意味着：
背板已确认故障
仅凭此关键词也无法确定故障组件是磁盘、磁盘托架、SATA 控制器还是路径中的其他组件。
可能原因 / 调查方向
- 磁盘
- 磁盘连接器 / 托盘
- 磁盘托架
- SATA 连接路径
- 背板
- SATA 控制器
关联性
- 将同一磁盘移动到另一个托架后仍然报告 ATA 总线错误：磁盘相关问题的可能性增加。
- 不同磁盘在同一托架中反复报告 ATA 总线错误：托架 / 背板 /SATA 路径问题的可能性增加。
- 多个托架中出现类似的 ATA 总线错误：进一步调查背板 /SATA 控制器 / 共享连接路径。
# 如何关联事件日志和内核日志？
例如，如果事件日志仅显示：
主机：磁盘 5：已断开连接
这仅告诉您系统观察到磁盘 5 已断开连接。
如果内核日志在相同时间戳附近也显示：
ata5: ATA 总线错误
ata5: 硬重置链接
您可以进一步将调查重点放在与该磁盘相关的 ATA 通信路径上。然而，这仍然只是一个可能原因 / 调查方向，而不是确认的硬件故障。
同样，如果事件日志报告Medium Error，内核日志报告UNC，并且磁盘健康 / 坏块扫描结果也异常，那么磁盘介质 / 读取错误的可能性比单独出现这些信息时更高。
模式关联参考
| 观察到的日志模式 |
优先调查方向 |
UNC + 中等错误 / 未恢复的读取错误 |
磁盘介质 / 坏扇区 |
UNC + 磁盘健康 I / O 错误 + 坏块扫描错误 |
磁盘 |
reset failed, giving up并且问题随磁盘移动 |
磁盘 |
reset failed, giving up在同一托架中反复发生在不同磁盘上 |
托架 / 背板 / SATA 路径 |
| 命令超时 + 重复链接重置 |
磁盘 / 连接 / SATA 控制器 |
| 多个磁盘在大约相同时间报告命令超时 |
共享硬件路径 / 控制器 / 系统级调查 |
ATA bus error在同一托架中反复发生 |
托架 / 背板 / SATA 路径 |
ATA bus error跟随磁盘 |
磁盘 |
磁盘断开连接 + ATA bus error |
ATA 通信 / 路径问题；需要进一步隔离 |
| 多个磁盘同时断开连接 |
不要假设是单一磁盘问题；调查共享路径 / 控制器 / 背板 / 电源 / 扩展路径 |
本表中的“较高优先级”仅指故障排除优先级，并不确认根本原因。
我不应该如何解读内核日志？
不要直接得出以下结论：
UNC = 磁盘肯定故障
重置失败 = 磁盘肯定故障
ATA 总线错误 = 背板肯定故障
命令超时 = 控制器肯定故障
更合适的分析流程是：
关键词
↓
识别错误类别
↓
查看周围的内核消息
↓
关联事件日志和时间戳
↓
识别磁盘 / 托架 /ATA 设备
↓
关联 SMART/ 磁盘健康 / 坏块结果
↓
关联磁盘 / 托架隔离测试
↓
建立可能原因 / 调查方向
↓
QNAP 技术支持进行较终分析
我应该向 QNAP 技术支持提供哪些信息？
- NAS 型号
- QTS/QuTS hero 固件版本和构建
- RAID 类型 /RAID 组状态
- 受影响的磁盘托架 / 插槽
- 磁盘型号 / 固件 / 序列号
- 磁盘掉线的确切时间戳
- 事件日志
- 诊断日志 ZIP
- SMART / 磁盘健康结果
- 坏块扫描结果（如果已执行）
- 磁盘 / 插槽交叉测试结果（如果已执行）
- 内核消息 / 初步分析中识别的关键词
- 关键词前后的相关内核日志上下文
如果您已进行初步分析，请描述结果为：
可能的调查方向：
磁盘 / SATA 链接 / 背板 / 控制器 / 媒体错误 / 等等
避免描述为：
确认的故障组件：
...
除非 QNAP 技术支持已完成分析并确认结果。
总结
优异磁盘掉线日志分析的目的不是从单个内核日志关键词中识别故障组件。相反，应结合事件日志、内核日志和实际故障排除结果，逐步缩小调查范围。
四个主要类别是：
- 链接失败 — 例如，
reset failed, giving up
- 不可恢复错误 — 例如，
UNC，Medium Error，Unrecovered read error
- 命令超时 — 磁盘命令未在预期时间内收到响应，可能伴随重复的链接重置
- 硬件故障 — 例如，
ATA bus error
关键词提供可能的原因 / 调查方向，而不是确认的根本原因。
较终的故障分析和硬件确定应基于 QNAP 技术支持对完整诊断日志、系统状态和隔离测试结果的审查。
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