> ## Documentation Index
> Fetch the complete documentation index at: https://docs.futurex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Manually zeroize old data

> Securely wipe partitions before encryption to prevent recovery of residual data.

For each partition where you are not preserving existing data (where **encrypted\_preserve=n**) and which previously held sensitive data, wipe the partition before encrypting it. Otherwise, some blocks might not be overwritten with encrypted data right away , and the original data could be recovered.

Use the **unmount**  and **wipefs** commands to unmount and zeroize partitions:

```shell expandable lines wrap title="Shell" theme={null}
$ umount <partition name>
$ wipefs <partition name>
$ cat /dev/zero > <partition name>
```

For example, to zeroize partition `/dev/sdb`:

```shell expandable lines wrap title="Shell" theme={null}
$ umount /dev/sdb
$ wipefs /dev/sdb
$ cat /dev/zero > /dev/sdb
```