Disk Fragmentation and Data Recovery Issues
What data fragmentation is and how it affects the quality of data recovery. Disk fragmentation is a fact of our daily life. It’s a well-known fact that fragmentation affects performance, specifically the speed of disk access operations. However, disk fragmentation also has another aspect that’s rarely mentioned. If something goes wrong, fragmented files are much more difficult to recover even if you’re using the best data recovery tools. Why’s that? Let’s begin from explaining what disk fragmentation is.
In today’s multi-tasking environments, files get deleted, created and then deleted again. This in turn creates gaps in available free space on the disk. What happens if there’s more than enough free space on the disk, Windows attempts to create a large file, but the largest continuous block of free space on the disk is smaller than the largest single block? The operating system will split the file into several fragments, using the largest continuous blocks first.
With daily work, fragmentation tends to accumulate quickly. The number of fragmented files will be quickly reaching the numbers of 3 to 15 per cent, and even more if the amount of free space available on the disk is not huge compared to its total capacity. If you run a defragmentation tool on the disk, you can see exactly how many files are fragmented.
Now, three or even 15 per cent of all files being fragmented does not sound that bad. Why should you be concerned with a number that low?
Fragmentation is normally only viewed as a performance bottleneck, and these fairly low numbers will probably affect the performance of a typical system very little. Let’s look, however, what types of files are likely to get fragmented. Windows system files? Nope. They’re among the least frequently modified files on the system, typically installed once and only updated when you update Windows or install a service pack. Program files? They’re getting touched even less.
The most likely files to get fragmented are the files that get written more often than others. Namely, office documents, working databases, downloaded emails, pictures, and video files (due to their large size if for no other reason). Those are exactly the type of files most users will try to recover first.
So what do we mean saying that “only” 3 to 15 per cent of all files on the disk are fragmented? Simple: it means that, statistically, 35% to 83% of important files such as Excel or Word documents, databases, pictures and videos will be fragmented at the moment your system turns bad. As we’ll see later, it’s very difficult and sometimes impossible (or, better say, not economically feasible) to completely recover fragmented files, so taking preventive measures to reduce or prevent fragmentation is important for the sake of data safety.
To fix errors in recovered *.jpg files, we recommend using Hetman File Repair.