Here's an article about reviewing ZFS snapshots and understanding path diffs to recover accidentally deleted data:
Reviewing ZFS Snapshots and Understanding Path Diffs
ZFS, the Zettabyte File System, is a combined file system and logical volume manager designed by Sun Microsystems. One of its key features is the ability to create snapshots of data at specific points in time, which can be useful for recovering accidentally deleted files. In this article, we'll discuss how to review ZFS snapshots and understand path diffs to recover deleted data.
What are ZFS Snapshots?
ZFS snapshots are point-in-time copies of your data. They are created incrementally, meaning only the changes since the last snapshot are saved, reducing storage usage. You can create multiple snapshots of your data, and each snapshot represents a specific state of your data.
Reviewing ZFS Snapshots
To review your ZFS snapshots, you can use the zfs list command. This command will list all the available snapshots along with their creation time, snapshot ID, and other relevant information.
zfs list
Understanding Path Diffs
When you accidentally delete a file, you can use ZFS's snapshot feature to recover it. However, if the file has been overwritten or moved, you'll need to understand path diffs to locate it in a snapshot.
A path diff is a comparison of the file path in the current dataset and the file path in the snapshot. If a file has been moved or renamed, the path diff will show the difference between the current path and the path in the snapshot.
To view the path diffs, you can use the zfs diff command. This command will show the differences between the current dataset and a specified snapshot.
zfs diff tank/data@yesterday tank/data
In the above command, tank/data@yesterday is the snapshot taken yesterday, and tank/data is the current dataset. The output will show the differences between the two, including deleted, modified, and added files.
Recovering Deleted Data
Once you've identified the snapshot containing the deleted file, you can recover it using the zfs revert command. This command will revert the current dataset to the state of the specified snapshot.
zfs revert tank/data tank/data@yesterday
In the above command, tank/data is the current dataset, and tank/data@yesterday is the snapshot containing the deleted file. The command will revert the current dataset to the state of the snapshot, effectively recovering the deleted file.