> ## 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

> Procedural guide to wipe partitions before encryption to prevent data recovery.

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

Use the **umount** and **wipefs** commands to unmount and zeroize.

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

For example, to zeroize partition `/dev/sdb`, run the following commands:

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