# Monitoring the Progress of dd Commands in Linux


As a Linux user, you've likely used the [`dd` command](https://developnsolve.com/understanding-the-linux-dd-command) at some point to copy data between devices or files. `dd` is a powerful tool, but one downside is that it doesn't show progress by default. This can be frustrating when copying large amounts of data.

Fortunately, there are some simple tricks to monitor the progress of `dd` operations.

## Why Showing Progress Matters

When cloning a drive or copying a large file with `dd`, it's helpful to visualize the progress. Without any progress output, `dd` makes it seem like nothing is happening and you don't know if the command is still working or has stalled. Showing progress gives you peace of mind that the copy is still in progress and when you can expect it to complete.

## Using status=progress with dd

The easiest way to monitor `dd` progress is to use the `status=progress` option:

```plaintext
sudo dd if=/dev/sda of=/dev/sdb status=progress
```

This will display periodic progress statistics like this:

```plaintext
194560+0 records in
194560+0 records out
996147200 bytes (1.0 GB, 931 MiB) copied, 5.56784 s, 179 MB/s
```

The output shows the number of records copied, bytes copied, and the copy rate. This gives you real-time insight into how `dd` is progressing.

## Sending SIGINFO signal

If you've already started a `dd` process and forgot to add the `status=progress` option, there is another method using signals.

You can have `dd` print an intermittent progress update by sending the `SIGINFO` signal to the running process:

```plaintext
killall -SIGINFO dd
```

Or if you know the process ID:

```plaintext
kill -SIGINFO <pid>
```

Either command will cause `dd` to print to stderr and show you the current progress without interrupting the copy.

## Using pv to Monitor Progress

For more flexibility in visualization, you can use a utility called `pv` (Pipe Viewer). `pv` allows piping data through and monitoring the transfer rate and progress in real-time.

To see `pv` in action:

```plaintext
dd if=/dev/sda | pv | dd of=/dev/sdb
```

As `dd` copies data, `pv` will display both the byte count and percentage complete. It also provides a progress bar and transfer speed. This gives even more detail into the file copy operation.

## Getting Progress for Files (not just Devices)

The previous examples are useful for copying full drives or partitions. But what about just copying a single file?

You can combine `dd` with `pv` to show progress when copying files too:

```plaintext
dd if=input.iso | pv | dd of=output.iso
```

By splitting the copy into smaller chunks that `pv` can analyze, you get the same progress view for file copies.

## Summary

- Use `dd status=progress` to easily add basic progress
- Send SIGINFO signals to print periodic status without interrupting `dd`
- Use `pv` in a pipe for more detailed progress statistics
- Monitor file copy progress with `dd`, `pv` and output files

Getting progress feedback is essential when copying large amounts of data with `dd`. Hopefully these tips help you better monitor `dd` commands and avoid wondering whether they are still working properly.

Keep an eye on the progress and enjoy some peace of mind for your `dd` data transfers.