One of the most exciting features Apple announced at WWDC 2016 was a new file system APFS (Apple File System) that’s going to replace CoreStorage, FileVault, FusionDrive, and the more than decade-old HFS by eventually becoming the default file system for all Apple gadgets in the coming years, from the Apple Watch to Mac computers.
Among other novelties APFS, currently available as part of the macOS Sierra beta, brings a long-anticipated file system mechanism called snapshot. In short, snapshot allows users to grab an instant copy of the file system at a specific point in time — effectively “freezing” data — while continuing to use and modify the file system while keeping old data intact. It does so in a space-efficient manner, where changes are tracked and only new data blocks take up additional space, which is extremely valuable for regular backup.
There are various snapshot technologies on the market, but the most well-known today is Microsoft Volume Shadow Copy Service (VSS), which is integrated into Windows XP and later. It’s no wonder most PC backup vendors utilize it instead of developing their own online backup solutions: Invoked by a supported backup utility (requestor, in Microsoft parlance), VSS saves the initial state of data blocks residing on disks by creating shadow copies for each volume involved in the process as virtual read-only devices. The backup utility then copies data from those shadow copies to a backup location, while OS and applications continue writing to the original volumes. This trick ensures consistency of backup data at any given moment, while allowing standard read/write operations for target storage devices during a backup process. Once the backup task is completed, the shadow copies are deleted.
Obviously, the arrival of similar snapshot functionality in APFS promises big changes to Time Machine, which promises to completely replace the creaky, aging mechanism of hard links that it builds and maintains – a slow and resource-consuming process. Currently, Time Machine has to wait until user applications are closed and locked files become available to process files, while ignoring system files at all, which is why OS X has a two-step restore procedure: Users first reinstall the operating system before restoring apps and user files from a backup image. Snapshot opens the door for fast, regular backup imaging of the entire system including user files, running applications, and operating system. By only saving changes when a file is updated, a snapshot-based backup app also requires much less disk space. All this promises that in the not-too-distant future, Time Machine backups could be faster and occupy less space than they do today.
In the meantime, the only snapshot technology available to Mac users is our Snapshot for Mac OEM. The concept of the Paragon Snapshot for Mac technology is based on embedding a special filter driver into a kernel input-output (I/O) stack between a block device and the file system. The goal is to save the initial state of data blocks on a disk at the time the snapshot is taken to provide backup data consistency, while the OS or applications continue modifying data on the same disk.
When attempting to write something to a block device for which a snapshot has been taken, the filter driver first copies existing data from the targeted blocks to a special temporary file called the backstore, and only then the writing operation is allowed. This way, Snapshot for Mac doesn’t prohibit rewriting data on the block device snapshot, but only postpones it until old data is copied to the backstore. Thus, for data blocks changed after a snapshot is taken, Snapshot for Mac provides a backup engine for initial data from the backstore, while unchanged blocks are stored directly on the device.
If you develop your own backup solution for Mac or represent a vendor of disaster recovery solutions for businesses of all sizes, you can make it even more robust by accelerating backup routines while increasing customer satisfaction and loyalty. Paragon Snapshot for Mac will help you to increase your target audience with companies whose businesses rely on Macs: For example, design firms, movie production studios, and more.
Paragon Snapshot for Mac OEM allows you to easily and quickly back up running applications and system-locked files, create RAW disk images, or an image of any volumes (e.g. NTFS or ExtFS-formatted Windows or Linux partitions).
In the newly updated version, Paragon Snapshot for Mac OEM doesn’t require a post-installation reboot, no longer loads and runs in the background when OS X starts up — all of which helps minimize any potential slowdown for the Mac. We designed it to achieve maximum productivity with a minimum of required operating system resources.
While Apple’s new file system promises the snapshot, Paragon Software delivers it — check out the full features of this amazing solution on our website!
- The first snapshot technology for OS X;
- The only solution for sector-level imaging;
- 2-4 times faster than file-level backup/restore procedures!