# Residency

> USearch for C#

Where the payload lives is the constructor's name, as in the C lifecycle verbs, so a residency an index lacks has no constructor to call.
Each takes only the placement its own hardware has, one shard per memory domain, device or path, and an empty list derives the placement.

```csharp
using DenseIndex inRam = DenseIndex.InitRam(options, memoryDomains: [0, 1]);      // One graph per socket
using DenseIndex inVram = DenseIndex.InitVram(options, devices: [0, 1, 2, 3]);    // Sharded, never replicated
using DenseIndex uploaded = DenseIndex.LoadVram("index.safegraphs", devices: [0, 1]);
using DenseIndex onDisk = DenseIndex.ViewNvme("index.safegraphs.json", paths: ["/mnt/nvme0"]);
```

An NVMe handle serves a checkpoint in place, and every mutating verb fails on it with `Status.ReadOnly`, as on a `DenseIndex.ViewRam`.
Until NVMe checkpoints carry keys, `ViewNvme` answers `Status.Unsupported`.