Pavel Losevsky - Fotolia
Are storage array-based snapshots preferable to other types of data snapshots (file system, hypervisor, etc.)? Why or why not?
As with many things in IT, there are both advantages and disadvantages to creating storage-level data snapshots. The main advantage is that storage-level snapshots do not tend to incur the performance impact of software snapshots. Software-based data snapshots are often (but not always) based on the use of differencing disks. This approach can have a significant impact on read performance as multiple snapshots are accumulated. Hardware-level data snapshots on the other hand, are oftentimes based on the use of pointers, which offer better performance.
By submitting your personal information, you agree that TechTarget and its partners may contact you regarding relevant content, products and special offers.
The main advantage offered by software-level snapshots is consistency. File-system-level data snapshots are almost always file-system consistent. This means that a snapshot will never contain a partially written file. In contrast, storage-level snapshots usually occur at the block level, and it is sometimes possible to take a storage-level snapshot while a file update is in progress, thereby resulting in a corrupt file (if the snapshot is ever rolled back).
Similarly, hypervisors try to provide application awareness. This means that when a hypervisor-level data snapshot occurs, the hypervisor attempts to create the snapshot in a way that places any applications running on virtual machines into a consistent state before the snapshot is created. Storage-level snapshots are generally not application-aware, so snapshots will likely be created with applications in an inconsistent state.
Dig Deeper on Disk-based backup
Related Q&A from Brien Posey
A ghost image can be used to copy the contents of one server to another for backup, but the process of creating ghost images may not be as simple as ...continue reading
Backup and recovery trends, such as hybrid cloud data protection, are gaining popularity in the IT industry. Are these three major trends part of ...continue reading
Can disaster recover planning save an organization from a costly IT outage? The British Airways IT disaster of 2017 has many wondering how to prevent...continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.