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Event ID 502: IO coalescing flush command generated

Windows Event ID Lookup: What Windows event IDs mean: 4625, 4624, 4740, 6008, 41, 7045, 1102 and 3,000 more, with Windows' own message text, the fields and what to check.

Look up a Windows event ID from Event Viewer, a SIEM alert or a log export: what it means, the fields it records, and what to check. Many IDs are used by more than one source (event 41 is both a Kernel-Power crash and a boot error), so every definition is shown, the one people usually mean first. The message text is Windows' own, read from the event providers of Windows 10.0.26200.0, 2026-10-28; the notes are ours, based on Microsoft's security auditing reference.

Try: 4625, 4624, 4740, 6008, 41, 1074, 7045, 1102, 4104, 1149

IO coalescing flush command generated.

Event 502
Kernel-Power
System log
Information
Message and fields (as Event Viewer shows them)
IO coalescing flush command generated.

File has been opened by an isolated reader.

Event 502
Ntfs
System log
Information
Message and fields (as Event Viewer shows them)
File has been opened by an isolated reader.

Storport Device (Port = …, Path = …, Target = …, Lun = …) was marked unresponsive due to reason

Event 502
StorPort
System log
Error
Message and fields (as Event Viewer shows them)
Storport Device (Port = …, Path = …, Target = …, Lun = …) was marked unresponsive due to reason : (…).                    
Corresponding Class Disk Device Guid is ….

Execution of idle task ID … has started.

Event 502
TaskScheduler
TaskScheduler/Operational log
Information
Message and fields (as Event Viewer shows them)
Execution of idle task ID … has started.

SMB2 Connection Terminated

Event 502
SMBServer
SMBServer/Operational log
Information
Message and fields (as Event Viewer shows them)
SMB2 Connection Terminated