---
title: IOUserStorageOptions
framework: BlockStorageDeviceDriverKit
role: symbol
role_heading: Type Alias
platforms: [driverkit 21.0+]
path: blockstoragedevicedriverkit/iouserstorageoptions
---

# IOUserStorageOptions

Options that affect the performance of read-write operations.

## Declaration

```occ
typedef uint32_t IOUserStorageOptions;
```

## Discussion

Discussion Use these options with the DoAsyncReadWrite function.

## Topics

### Storage Options

- [kIOUserStorageOptionNone](blockstoragedevicedriverkit/kiouserstorageoptionnone.md)
- [kIOUserStorageOptionForceUnitAccess](blockstoragedevicedriverkit/kiouserstorageoptionforceunitaccess.md)

## See Also

### Accessing the Device

- [DoAsyncUnmap](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncunmap.md)
- [BlockRange](blockstoragedevicedriverkit/blockrange.md)
- [DoAsyncSynchronize](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncsynchronize.md)
- [DoAsyncEjectMedia](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncejectmedia.md)
- [Complete](blockstoragedevicedriverkit/iouserblockstoragedevice/complete.md)
- [DoAsyncReadWrite](blockstoragedevicedriverkit/iouserblockstoragedevice/doasyncreadwrite.md)
- [CompleteIO](blockstoragedevicedriverkit/iouserblockstoragedevice/completeio.md)