---
name: "zfs_prepare_disk"
section: "8"
platform: "linux"
package: "zfsutils-linux"
version: "2.3.9-0+deb13u1"
release: "Debian 13 (Trixie)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/zfs_prepare_disk"
---

# zfs\_prepare\_disk(8)

special script that gets run before bringing a disk into a pool

## NAME

**zfs\_prepare\_disk** – special script that gets run before bringing a disk into a pool

## DESCRIPTION

**zfs\_prepare\_disk** is an optional script that gets called by libzfs before bringing a disk into a pool. It can be modified by the user to run whatever commands are necessary to prepare a disk for inclusion into the pool. For example, users can add lines to **zfs\_prepare\_disk** to do things like update the drive's firmware or check the drive's health. **zfs\_prepare\_disk** is optional and can be removed if not needed. libzfs will look for the script at /usr/lib/zfs-linux/zfs\_prepare\_disk.

### Properties

**zfs\_prepare\_disk** will be passed the following environment variables:

- **POOL\_NAME**

  Name of the pool

- **VDEV\_PATH**

  Path to the disk (like /dev/sda)

- **VDEV\_PREPARE**

  Reason why the disk is being prepared for inclusion ('create', 'add', 'replace', or 'autoreplace'). This can be useful if you only want the script to be run under certain actions.

- **VDEV\_UPATH**

  Path to one of the underlying devices for the disk. For multipath this would return one of the /dev/sd\* paths to the disk. If the device is not a device mapper device, then **VDEV\_UPATH** just returns the same value as **VDEV\_PATH**

- **VDEV\_ENC\_SYSFS\_PATH**

  Path to the disk's enclosure sysfs path, if available

Note that some of these variables may have a blank value. **POOL\_NAME** is blank at pool creation time, for example.

## ENVIRONMENT

**zfs\_prepare\_disk** runs with a limited $PATH.

## EXIT STATUS

**zfs\_prepare\_disk** should return 0 on success, non-zero otherwise. If non-zero is returned, the disk will not be included in the pool.