---
title: FSVolume.SetXattrPolicy.mustReplace
framework: fskit
role: symbol
role_heading: Case
path: fskit/fsvolume/setxattrpolicy/mustreplace
---

# FSVolume.SetXattrPolicy.mustReplace

Set the value, but fail if the extended attribute doesn’t already exist.

## Declaration

```swift
case mustReplace
```

## See Also

### Declaring a policy

- [FSVolume.SetXattrPolicy.alwaysSet](fskit/fsvolume/setxattrpolicy/alwaysset.md)
- [FSVolume.SetXattrPolicy.mustCreate](fskit/fsvolume/setxattrpolicy/mustcreate.md)
- [FSVolume.SetXattrPolicy.delete](fskit/fsvolume/setxattrpolicy/delete.md)