# DurabilityFault

`import { DurabilityFault } from "destack:simulation/fault";`

Storage durability fault.

```ds title="DurabilityFault"
export enum DurabilityFault {
    AckWithoutSync = 1,
    LoseAcknowledgedWrite = 2,
    SyncNoop = 3,
    MetadataNotDurable = 4,
    AckBeforeQuorumPersist = 5,
}
```

[language/library/src/simulation/fault/fault.ds:183:194](https://github.com/destack-sh/destack/blob/main/language/library/src/simulation/fault/fault.ds#L183-L194)

## Variants

### `AckWithoutSync = 1`

Acknowledge writes before durability barriers complete.

### `LoseAcknowledgedWrite = 2`

Lose one write that was already acknowledged.

### `SyncNoop = 3`

Report sync success without enforcing durability.

### `MetadataNotDurable = 4`

Persist file payload without required metadata durability.

### `AckBeforeQuorumPersist = 5`

Acknowledge one distributed write before quorum durability.