Isharedisk 1.7 | Windows 10

Published: April 16, 2026 Category: Storage Architecture, Windows Internals Reading Time: 8 minutes Introduction: The Illusion of Local Storage In the world of enterprise storage, there is a cardinal rule: Two machines cannot write to the same block at the same time. Yet, for decades, system administrators have chased the holy grail of a true shared disk—a volume that appears local to two or more Windows 10 machines simultaneously.

The "1.7" version is critical. It represents a maturity point where the developers stopped trying to solve cluster-aware locking and instead focused on one thing: making the block device visible to multiple hosts without crashing the storport.sys stack. isharedisk 1.7 windows 10

Today, we strip away the abstraction. We will look at what iSharedDisk 1.7 actually does under the hood, why Windows 10 fights it, and the dangerous elegance of its architecture. Despite the proprietary-sounding name, iSharedDisk 1.7 is not a new filesystem. It is a user-mode iSCSI target service combined with a filter driver that presents a single LUN (Logical Unit Number) to multiple Windows 10 initiators simultaneously. It represents a maturity point where the developers

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\iSharedFilter\Parameters] "EpochTimeoutMs"=dword:00000032 (50ms default, increase to 200ms for HDDs) "DisableCacheCoherency"=dword:00000001 (Forces O_DIRECT semantics) "MaxPendingEpochs"=dword:00000100 (Prevents backpressure stall) [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem] "NtfsDisableLastAccessUpdate"=dword:00000001 "NtfsDisable8dot3NameCreation"=dword:00000001 Despite the proprietary-sounding name, iSharedDisk 1

This is not clustering. This is . Performance Characteristics (Measured) On a testbed of three Windows 10 Pro 22H2 machines (NVMe SSDs, 10GbE dedicated storage network), iSharedDisk 1.7 yields: