# \*\*\*Resources\*\*\* Overview of ZFS Snapshots in Unraid

**URL:** <https://forum.hhf.technology/t/resources-overview-of-zfs-snapshots-in-unraid/190>\
**Category:** Resources\
**Tags:** zfs, unraid\
**Created:** [August 21, 2024, 12:19pm UTC](https://forum.hhf.technology/t/resources-overview-of-zfs-snapshots-in-unraid/190 "2024-08-21T12:19:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![hhf.technoloy](https://forum.hhf.technology/user_avatar/forum.hhf.technology/hhf.technoloy/32/68_2.png) [@hhf.technoloy](https://forum.hhf.technology/u/hhf.technoloy)\
**Post date:** [August 21, 2024, 12:19pm UTC](https://forum.hhf.technology/t/resources-overview-of-zfs-snapshots-in-unraid/190/1 "2024-08-21T12:19:00Z")

</div>

## Overview of ZFS Snapshots in Unraid

ZFS (Zettabyte File System) is a powerful file system that offers advanced features such as snapshots, which are crucial for data management and recovery. Implementing ZFS on Unraid can enhance your storage capabilities, particularly for users looking to maintain robust data integrity and backup solutions. This guide will provide a detailed approach to setting up and managing ZFS snapshots within an Unraid environment.

## Setting Up ZFS on Unraid

### Prerequisites

1. **Unraid Installation** : Ensure you have Unraid installed and running.
2. **ZFS Plugin** : Install the ZFS plugin from the Unraid Community Applications.
3. **Scripts and Cron Jobs** : Familiarize yourself with setting up scripts and cron jobs, as these will be essential for automating snapshot creation.

### Creating a ZFS Pool

To begin using ZFS, you need to create a pool:

```bash
zpool create mypool raidz /dev/sdX /dev/sdY /dev/sdZ

```

Replace `mypool` with your desired pool name and `/dev/sdX`, `/dev/sdY`, `/dev/sdZ` with your disk identifiers.

## Managing ZFS Snapshots

### Creating Snapshots

Snapshots in ZFS are read-only copies of the file system at a specific point in time. To create a snapshot, use the following command:

```bash
zfs snapshot mypool/dataset@snapshot_name

```

Replace `mypool/dataset` with your dataset name and `snapshot_name` with a descriptive name for the snapshot.

### Automating Snapshot Creation

To automate the creation of snapshots, you can use a script combined with cron jobs. Below is an example script that creates snapshots at specified intervals:

```bash
#!/bin/bash
# zfs-auto-snapshot.sh

# Define variables
POOL="mypool"
DATASET="dataset"
SNAPSHOT_NAME="$(date +%Y-%m-%d_%H-%M-%S)"

# Create snapshot
zfs snapshot ${POOL}/${DATASET}@${SNAPSHOT_NAME}

```

Save this script in a directory such as `/mnt/user/scripts/zfs-auto-snapshot.sh`, and make it executable:

```bash
chmod +x /mnt/user/scripts/zfs-auto-snapshot.sh

```

### Setting Up Cron Jobs

To schedule the script, edit the crontab:

```bash
crontab -e

```

Add the following line to run the script daily at midnight:

```bash
0 0 * * * /mnt/user/scripts/zfs-auto-snapshot.sh

```

This will ensure that a new snapshot is created every day.

## Managing Snapshot Retention

To manage how many snapshots you keep, modify your script to include logic for deleting old snapshots. For instance, to keep only the latest 28 snapshots:

```bash
#!/bin/bash

# Define variables
POOL="mypool"
DATASET="dataset"
SNAPSHOT_NAME="$(date +%Y-%m-%d_%H-%M-%S)"

# Create new snapshot
zfs snapshot ${POOL}/${DATASET}@${SNAPSHOT_NAME}

# Delete old snapshots, keeping only the latest 28
zfs list -H -o name -t snapshot | grep "${POOL}/${DATASET}@" | sort | head -n -28 | xargs -r zfs destroy

```

### Accessing Snapshots via Samba

To access snapshots through Samba, configure your SMB settings in Unraid:

1. Navigate to **Shares** \> **Add Share**.
2. Set up the share path to your dataset.
3. Add the following configuration in the SMB settings:

```ini
[data]
path = /mnt/user/mypool/dataset
browseable = yes
guest ok = yes
writeable = yes
read only = no
create mask = 0775
directory mask = 0775
vfs objects = shadow_copy2
shadow: snapdir = .zfs/snapshot
shadow: sort = desc
shadow: format = zfs-auto-snap_%S-%Y-%m-%d-%H%M
shadow: localtime = yes

```

This setup allows users to browse snapshots through Samba shares.

## Monitoring and Scrubbing Pools

Regularly monitor your ZFS pools using:

```bash
zpool status -v mypool

```

Additionally, perform scrubs periodically (recommended monthly) to ensure data integrity:

```bash
zpool scrub mypool

```

## Conclusion

Implementing ZFS on Unraid provides users with powerful data management capabilities through its snapshot feature. By automating snapshot creation and retention management, users can ensure their data is consistently backed up and recoverable. Regular monitoring and scrubbing of pools further enhance data integrity, making ZFS an excellent choice for advanced users looking to optimize their Unraid systems.