diff --git a/src/osal.c b/src/osal.c
index 80728283..655f104f 100644
--- a/src/osal.c
+++ b/src/osal.c
@@ -104,6 +104,35 @@ extern NTSTATUS NTAPI NtFreeVirtualMemory(IN HANDLE ProcessHandle,
                                           IN OUT PULONG RegionSize,
                                           IN ULONG FreeType);
 
+typedef struct _IO_STATUS_BLOCK {
+  union {
+    NTSTATUS Status;
+    PVOID Pointer;
+  };
+  ULONG_PTR Information;
+} IO_STATUS_BLOCK, *PIO_STATUS_BLOCK;
+
+typedef struct _FILE_PROVIDER_EXTERNAL_INFO_V1 {
+  ULONG Version;
+  ULONG Algorithm;
+  ULONG Flags;
+} FILE_PROVIDER_EXTERNAL_INFO_V1, *PFILE_PROVIDER_EXTERNAL_INFO_V1;
+
+#ifndef STATUS_OBJECT_NOT_EXTERNALLY_BACKED
+#define STATUS_OBJECT_NOT_EXTERNALLY_BACKED ((NTSTATUS)0xC000046DL)
+#endif
+#ifndef STATUS_INVALID_DEVICE_REQUEST
+#define STATUS_INVALID_DEVICE_REQUEST ((NTSTATUS)0xC0000010L)
+#endif
+
+extern NTSTATUS
+NtFsControlFile(IN HANDLE FileHandle, IN OUT HANDLE Event,
+                IN OUT PVOID /* PIO_APC_ROUTINE */ ApcRoutine,
+                IN OUT PVOID ApcContext, OUT PIO_STATUS_BLOCK IoStatusBlock,
+                IN ULONG FsControlCode, IN OUT PVOID InputBuffer,
+                IN ULONG InputBufferLength, OUT OPTIONAL PVOID OutputBuffer,
+                IN ULONG OutputBufferLength);
+
 #endif /* _WIN32 || _WIN64 */
 
 /*----------------------------------------------------------------------------*/
@@ -746,7 +775,89 @@ int mdbx_msync(mdbx_mmap_t *map, size_t offset, size_t length, int async) {
 
 int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t length, size_t limit) {
 #if defined(_WIN32) || defined(_WIN64)
-  NTSTATUS rc = NtCreateSection(
+  map->section = 0;
+  map->address = MAP_FAILED;
+
+  if (GetFileType(map->fd) != FILE_TYPE_DISK)
+    return ERROR_FILE_OFFLINE;
+
+  FILE_REMOTE_PROTOCOL_INFO RemoteProtocolInfo;
+  if (GetFileInformationByHandleEx(map->fd, FileRemoteProtocolInfo,
+                                   &RemoteProtocolInfo,
+                                   sizeof(RemoteProtocolInfo))) {
+    if ((RemoteProtocolInfo.Flags & (REMOTE_PROTOCOL_INFO_FLAG_LOOPBACK |
+                                     REMOTE_PROTOCOL_INFO_FLAG_OFFLINE)) !=
+        REMOTE_PROTOCOL_INFO_FLAG_LOOPBACK)
+      return ERROR_FILE_OFFLINE;
+  }
+
+  NTSTATUS rc;
+#ifdef _WIN64
+  struct {
+    WOF_EXTERNAL_INFO wof_info;
+    union {
+      WIM_PROVIDER_EXTERNAL_INFO wim_info;
+      FILE_PROVIDER_EXTERNAL_INFO_V1 file_info;
+    };
+    size_t reserved_for_microsoft_madness[42];
+  } GetExternalBacking_OutputBuffer;
+  IO_STATUS_BLOCK StatusBlock;
+  rc = NtFsControlFile(map->fd, NULL, NULL, NULL, &StatusBlock,
+                       FSCTL_GET_EXTERNAL_BACKING, NULL, 0,
+                       &GetExternalBacking_OutputBuffer,
+                       sizeof(GetExternalBacking_OutputBuffer));
+  if (rc != STATUS_OBJECT_NOT_EXTERNALLY_BACKED &&
+      rc != STATUS_INVALID_DEVICE_REQUEST)
+    return NT_SUCCESS(rc) ? ERROR_FILE_OFFLINE : ntstatus2errcode(rc);
+#endif
+
+  WCHAR PathBuffer[INT16_MAX];
+  DWORD VolumeSerialNumber, FileSystemFlags;
+  if (!GetVolumeInformationByHandleW(map->fd, PathBuffer, INT16_MAX,
+                                     &VolumeSerialNumber, NULL,
+                                     &FileSystemFlags, NULL, 0))
+    return GetLastError();
+
+  if ((flags & MDBX_RDONLY) == 0) {
+    if (FileSystemFlags & (FILE_SEQUENTIAL_WRITE_ONCE | FILE_READ_ONLY_VOLUME |
+                           FILE_VOLUME_IS_COMPRESSED))
+      return ERROR_FILE_OFFLINE;
+  }
+
+  if (!GetFinalPathNameByHandleW(map->fd, PathBuffer, INT16_MAX,
+                                 FILE_NAME_NORMALIZED | VOLUME_NAME_NT))
+    return GetLastError();
+
+  if (_wcsnicmp(PathBuffer, L"\\Device\\Mup\\", 12) == 0)
+    return ERROR_FILE_OFFLINE;
+
+  if (GetFinalPathNameByHandleW(map->fd, PathBuffer, INT16_MAX,
+                                FILE_NAME_NORMALIZED | VOLUME_NAME_DOS)) {
+    UINT DriveType = GetDriveTypeW(PathBuffer);
+    if (DriveType == DRIVE_NO_ROOT_DIR &&
+        wcsncmp(PathBuffer, L"\\\\?\\", 4) == 0 &&
+        wcsncmp(PathBuffer + 5, L":\\", 2) == 0) {
+      PathBuffer[7] = 0;
+      DriveType = GetDriveTypeW(PathBuffer + 4);
+    }
+    switch (DriveType) {
+    case DRIVE_CDROM:
+      if (flags & MDBX_RDONLY)
+        break;
+    // fall through
+    case DRIVE_UNKNOWN:
+    case DRIVE_NO_ROOT_DIR:
+    case DRIVE_REMOTE:
+    default:
+      return ERROR_FILE_OFFLINE;
+    case DRIVE_REMOVABLE:
+    case DRIVE_FIXED:
+    case DRIVE_RAMDISK:
+      break;
+    }
+  }
+
+  rc = NtCreateSection(
       &map->section,
       /* DesiredAccess */ SECTION_MAP_READ | SECTION_EXTEND_SIZE |
           ((flags & MDBX_WRITEMAP) ? SECTION_MAP_WRITE : 0),
@@ -755,11 +866,8 @@ int mdbx_mmap(int flags, mdbx_mmap_t *map, size_t length, size_t limit) {
                                                         : PAGE_READWRITE,
       /* AllocationAttributes */ SEC_RESERVE, map->fd);
 
-  if (!NT_SUCCESS(rc)) {
-    map->section = 0;
-    map->address = MAP_FAILED;
+  if (!NT_SUCCESS(rc))
     return ntstatus2errcode(rc);
-  }
 
   map->address = NULL;
   SIZE_T ViewSize = limit;