# Data Migration Guide

This guide covers moving data from existing S3-compatible systems to Aurora.

> Available S3 endpoint: `a-s3.aur.lu` (France, Albi).

## Strategy overview

- Inventory and segment data by bucket/prefix.
- Decide on transfer tooling (AWS CLI, [rclone](https://docs.aur.lu/docs/s3/tools/rclone), SDKs).
- Use multipart uploads for large files.
- Validate integrity (size, ETag, checksums, counts).
- Cutover with delta sync, then switch writers.

## Option 1: rclone

```bash
# Initial bulk copy
rclone copy s3:source-bucket aurora:dest-bucket --progress --s3-no-check-bucket --transfers 16 --checkers 32

# Delta sync just before cutover
rclone sync s3:source-bucket aurora:dest-bucket --progress --s3-no-check-bucket --transfers 16 --checkers 32
```

## Integrity validation

- Count objects per prefix and compare.
- Compare total bytes transferred.
- Spot-check object downloads and verify checksums.
- Use `list-object-versions` if migrating versioned buckets.

## Permissions and security

- Create minimally privileged keys per migration job.
- Avoid Delete permissions during migration.
- If using Object Lock, ensure retention allows copying required metadata.