---
title: "Sync again and Run again"
url: https://storagestudio.us/wiki/sync-again
category: "Data Transfers"
tags: ["data transfers", "sync", "cloud accounts"]
summary: "A finished, failed or cancelled transfer offers Sync again (for syncs) or Run again (for copies and moves), which repeats it with the same settings and sends only what changed since last time."
updated: 2026-10-01T05:33:49.000Z
---

# Sync again and Run again

A finished, failed or cancelled transfer offers Sync again (for syncs) or Run again (for copies and moves), which repeats it with the same settings and sends only what changed since last time.

**Sync again** and **Run again** repeat a transfer you've already set up, with the same source, destination and settings. The transfer compares both sides and sends only what is new or has changed, so topping up a large folder is quick when little has changed.

## Where to find it

Select a transfer in the **Data Transfers** list. Once it has **Completed**, **Failed** or been **Canceled**, the button row at the top of its details shows:

- **Sync again** for a **Sync (one-way)** or a **Bidirectional sync**;
- **Run again** for a **Copy** or a **Move**.

The new run appears in the same row of the list as the earlier ones, with the run count going up by one.

## What it sends

Each run looks at both sides and transfers only the differences: new files, and files whose size, date or content has changed. Files that already match are left alone. That makes **Sync again** the easy way to bring a big folder up to date, or to finish a transfer that failed or was cancelled part-way — files that had finished aren't sent a second time.

The operation still behaves as it always does. A **Sync (one-way)** run still deletes files at the destination that aren't in the source, and a **Bidirectional sync** run still carries deletions both ways. See [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync).

```mermaid
%% caption: What a repeat run does with each file
flowchart TD
  A[You click Sync again or Run again] --> B[Both sides are compared]
  B --> C{Is the file the same on both sides?}
  C -->|Yes| S[Skipped]
  C -->|No, new or changed| T[Transferred]
  B --> D{Sync one-way only: extra files at the destination?}
  D -->|Yes| X[Deleted from the destination]
```

*Flowchart — What a repeat run does with each file. Outline:*

- You click Sync again or Run again
  - leads to Both sides are compared
- Both sides are compared
  - leads to Is the file the same on both sides?
  - leads to Sync one-way only: extra files at the destination?
- Is the file the same on both sides?
  - Yes: leads to Skipped
  - No, new or changed: leads to Transferred
- Sync one-way only: extra files at the destination?
  - Yes: leads to Deleted from the destination

## Settings a repeat run doesn't carry over

- **Dry run** is switched off. Running a dry run again performs the transfer for real — handy once you've checked the preview, but worth knowing. See [Trying a transfer first with Dry run](https://storagestudio.us/wiki/dry-run).
- **First run for this pair** is never carried over for a **Bidirectional sync**. That box is for the very first run only; see [Two-way sync and the First run box](https://storagestudio.us/wiki/two-way-sync-first-run).

## When it isn't offered

- **While the transfer is still running, queued or paused.** Use **Pause**, **Resume** or **Cancel** instead.
- **For a Download.** A large download already picks up where it left off when it's resumed.
- **For a Move (Overwrite) started from Data Parking**, because the source is gone once that kind of move finishes.

If the same transfer is already running, clicking the button again doesn't start a second copy of it.

## Run again on a repeating transfer

A repeat of a scheduled transfer runs in the background at low priority, like its scheduled runs. It doesn't change the schedule — the next scheduled run still happens at its usual time. See [Scheduling a transfer](https://storagestudio.us/wiki/transfer-schedules).

More answers: https://storagestudio.us/faq

See also: [Data Transfers](https://storagestudio.us/wiki/data-transfers) · [What happens to transfers when you restart](https://storagestudio.us/wiki/transfers-and-restarts) · [A transfer failed](https://storagestudio.us/wiki/a-transfer-failed)

## What links here

- [A transfer failed](https://storagestudio.us/wiki/a-transfer-failed)
- [Copy, Move, Sync or Two-way sync](https://storagestudio.us/wiki/copy-move-sync-or-two-way-sync)
- [Data Transfers](https://storagestudio.us/wiki/data-transfers)
- [Files that change while they're being transferred](https://storagestudio.us/wiki/files-that-change-during-a-transfer)
- [Letting another AI assistant read your storage](https://storagestudio.us/wiki/ai-access)
- [Scheduling a transfer](https://storagestudio.us/wiki/transfer-schedules)
- [Trying a transfer first with Dry run](https://storagestudio.us/wiki/dry-run)
- [Two-way sync and the First run box](https://storagestudio.us/wiki/two-way-sync-first-run)
- [What happens to transfers when you restart](https://storagestudio.us/wiki/transfers-and-restarts)