The cloud is changing data storage and protection in fundamental ways, and the snapshot is no exception. Snapshots are images of a disk at particular points in time. While the first snapshot generally covers an entire disk, the subsequent ones only capture the changes, ensuring more efficient use of capacity and bandwidth. Snapshots have long been a valuable enterprise storage tool, but before the cloud, they were not considered a viable alternative to traditional data protection due to their limitations. Thanks to Nasuni’s UniFS® and the cloud, that is no longer true, and in this post I will explain how snapshots can replace backup as a continuous data protection solution.
How Do Data Snapshots Work?
Before we go into those details, consider how snapshots work. Snapshots are either taken at the level of the block – the fundamental unit of data storage – or the chunk, which incorporates metadata in addition to the raw storage. After that initial image, any change to a block or chunk is noted and time-stamped and saved as part of each snapshot. The process of capturing a snapshot is fast, but not instantaneous. Think about trying to take a large family photograph. Someone is always moving, refusing to freeze for the picture. In the same way, users are often reading, writing and making changes to disks while snapshots are in progress. To address this issue, companies have developed technologies that effectively hold the image still during the snapshot. These solutions track the changes, but they can impact overall performance during the snapshot.
The Three Problems With Using Traditional Snapshots for Protection
Snapshots allow you to quickly roll back your system to a specific point in time, but there are three major problems with using traditional snapshots for data protection.
The technology typically writes the snapshots to the same disk it copies
In one sense, this is great because the snapshots are local and easily accessible, which translates into quick rollbacks. But these snapshots could never be used for data protection because they would never survive the failure of that disk.
Traditional Snapshots use up precious capacity on the local disk, increasing costs
Primary file storage is already growing at unprecedented rates. Companies are having enough trouble finding the capacity to manage their unstructured data; they do not need to fill up expensive local disk space with snapshots.
Snapshot solutions typically limit the number of snapshots you can retain
Each snapshot has to be tracked with metadata, including timestamps and tags, so file systems put a cap on the number of snapshots. This translates into a limit on the amount of history you can keep, and a viable data protection system should have no cap on history. All of a company’s data should be protected and recoverable in the most efficient way possible.
There are snapshot solutions that circumvent some of these flaws. Snapshot vaulting and snapshot mirroring move the snapshots to other disk-based systems, reducing the burden on primary storage. Snapshot vaulting is better suited for standard backup, but even then there are limitations on the retention and added expense to keeping them on disk, so companies often still have a separate backup solution for long-term storage. Snapshot mirroring is more of a disaster recovery solution. All file data is replicated – or mirrored – to another site, and in the event of a local disaster, you can retrieve your history from that remote array. Furthermore, since you are dealing with an image on a disk, the restores are faster.
Does any of this sound familiar? It should because vaulting and mirroring are fundamentally not that different from running disk-to-disk backup or offsite replication. The process is more efficient, but the data is still moving from one physical medium to another. You still need replication software, excess bandwidth, physical disks and a location to host everything, plus the budget to pay the added licensing fees. Companies have begun offering vaulting and mirroring to the cloud, but these solutions burden IT with another system and another vendor – the cloud storage provider – to manage.
Snapshot Efficiency at Cloud Scale
Nasuni File Services adopts the best properties of snapshots – efficient capture and storage of changes and fast rollbacks – and merges them with the cloud to create a new kind of data protection. Instead of being forced to rely on separate processes for snapshots and long-term backups, companies deploy a single, comprehensive solution that snapshots their entire history to the cloud. So how is this possible? The only way to use snapshots as the building blocks of a continuous data protection solution is to retain an unlimited history, and thanks to our patented UniFS® technology, Nasuni Cloud NAS is the only solution that retains unlimited, perpetual snapshots. The technical background on how UniFS can efficiently accomplish this can be found in our patent filings, but the end result, from a protection standpoint, is that we have been able to combine snapshots and backups into a single entity.
Nasuni can be set to capture snapshots as frequently as any other solution and all of those snapshots are securely stored in the cloud. Users can easily self-restore files, and IT can re-establish access to business files within minutes of a disaster. Finally, Nasuni wraps everything into a solution with single-pane-of-glass management and numerous additional advantages. There are no extra charges. No hidden or unexpected licensing fees. You don’t have to deal with the cloud on your own, or worry about managing multiple solutions from different vendors. The snapshot-based protection at the core of Nasuni is seamless, cost effective and secure. As a result, Nasuni makes IT’s job easier and enterprises more productive.
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