 Hello everybody! Watch this video to learn about top tools to recover data from ZFS drives. ZFS is a revolutionary file system that follows an absolutely different approach to administration of file systems while offering new features and advantages that no other file system can provide at the moment. ZFS is reliable, scalable, and easy to manage. ZFS moves away from conventional file system principles by dropping the concept of volumes. Instead, ZFS offers more complicated storage pools that consist of one or more data media. Such media can be added to the pool or removed from it, if and when necessary. File systems are then dynamically expanded or reduced without having to format specific media. ZFS ensures a format of disks that is constantly harmonized and cardimative. Such pattern guarantees that disk data is not overwritten for quite a long time, and all updates to the file system are made at the lowest level. However, just as any other file system, ZFS is not perfect, and it sometimes suffers from crashes and data loss. In today's video, we are going to test top tools able to recover such data from this file system. For starters, let's explore the ZFS structure. It is divided into seven main elements. SPA, storage pool allocator, DSL, data and snapshot layer, DMU, data management unit, ZAP, ZFS attribute processor, ZPL, ZFS post-exlayer, ZIL, ZFS intent log, and ZVOL, which stands for ZFS volume. ZFS pools are built as combinations of virtual devices of two types. Physical and logical virtual devices. Physical VDFs or virtual devices are writable block devices, for example hard disks, while logical VDFs are combined groups of physical disks. All VDFs create a tree, the leaves of which are represented by physical devices. All pools have a special logical VDF, which is the root of such tree. All branches of the root VDF are known as top-level virtual devices. Every physical virtual device contains a structure of 256 kilobytes known as VDF label. It contains information about this device and all virtual devices with which it shares at top-level VDF. The label comprises four parts, 8 kilobytes of blank space, 8 kilobytes of boot header, 112 kilobytes of name or value pairs, and 128 kilobytes of space occupied by 1 kilobyte overblock structures. Unlike other final systems, ZFS does not have such a thing as superblock, but it has a VDF label instead. In the structure, there are four of them, each occupying 256 kilobyte of space. This is where they are located. Level 0 and label 1 at the beginning of the disk. The second and the third are positioned similarly, but at the end of the disk. Inside VDF labels, there are uberblocks that contain links to data. If one of VDF labels is erased, a data-recover tool may have some difficulty in searching for information on the disk. In today's video, we are going to show you how to recover deleted data from a ZFS drive and how to recover data if a part of the file's system structure is gone. In a Linux operating system, I created a ZFS pool, wrote some data to the disk, a few folders containing photos, videos and documents, and then removed some of them. For our benchmarking assessment, we have selected several popular data recovery tools – Hetman RAID Recovery, Recleamy, UFS Explorer, Disk Drill, Wondershare Recovery, and RSAVER. Alright, let's get down to testing. Let's connect the ZFS disk. Users can't recognize this file system, and when the drive is connected, the operating system suggests formatting it, so that the disk can be used. However, in fact, there is no need to format anything – start Hetman RAID Recovery and scan the disk. You can see that the program can recognize the disk, detect its file system, and display its name and size properly. To view the contents and find the deleted files, right-click on the disk and choose Open. In this case, a fast scan should be enough. This type of analysis will scan the disk quickly and display the results. You can see them on the screen. In this scenario, the tool has no difficulty in finding the files deleted in such a way, and it displays them marked with a red cross. Full analysis and signature search are not required for this case. Considering they take much longer to complete, it saved us quite a lot of time. The contents of all files can be checked with the preview feature, and you can search files by name, which helps you find the necessary data even quicker. Now all the files have been recovered. What is more, the disk structure is retained, so all files and folders can be found where they used to be, and it makes searching for lost data extremely easy. In a very short time and with little effort, the program was able to find and recover the data previously removed from a ZFS disk. Let's try another candidate, EFS Explorer. It shows the disk name, capacity, and ZFS partition below. When you view the contents of this directory, only the files which are still on the disk are displayed, but you can't see the ones that have been deleted. Let's run a quick scan. The result is similar. Now, let's start searching for lost files. Unchecking necessary options? If you don't do that, the search will take longer. This is a disadvantage for novice users who are unlikely to notice and disable all those options. Searching for lost files on a relatively small 15-gigabyte drive took over 15 minutes. Scanning a disk of larger capacity will certainly require much more time. As a result, the program has found the deleted data. It is marked with a different color, but only photos can be previewed. This is another drawback, because we cannot understand if they could be recovered in the end and if they are going to be damaged or not. Also, it is very inconvenient to know so little about your chances of recovery before you actually buy the tool. Let's try another candidate, Reclaiming. The initial screen doesn't show the disks. At first, you need to set up a proxy server, then skip the registration window, and then configure disk scan options. After that, the program will start analyzing connected hard disks and then display their list on the screen, which also takes some time. The program reads service information, identifies the file system, names and so on. When the process is over, we can see the list of recognized devices. Here is the test disk, and when we expand it, you can see a ZFS partition. Select it and start the scan. In the next window, you can choose the scan type. We leave the recommended option as it is. Uncheck unnecessary file system options. The program has identified the file system, but nevertheless, all file system variants are activated. If all variants are selected, the scan will take much longer, so that's why we choose to uncheck the unnecessary ones and then click start. As a result, the program has found some files. Only the contents of a raw folder can be previewed, and other files are not displayed. The deleted files are not shown either, their names are not preserved, the disk structure is damaged and the program couldn't find any documents. Most likely a deeper scan is required to find the deleted files, so let's click resume to start. The deep scan of a 15-gigabyte drive took over 30 minutes. When scanning, this program uses a signature search. You can tell it by how the files are sorted. When dealing with the drive of big capacity, the process can be really long. As a result, documents are not available for preview and some of the photos we have found are damaged. The same happened to video files, some of them got damaged and can't be played properly. The structure and file names are lost, many files are damaged and will not be recovered completely. The next one on the list is disk grill. The program can see the storage device, its name and capacity, but the file system is not recognized. Quick scan is not available for this disk, as the program was unable to identify its file system, so all you can do is to use a deeper scan. Click search for lost data. With such scan, the program also looks for files but there are signatures. In this case, file names and disk structure are not preserved and the scan takes a pretty long time to complete. It turned out to be longer than with the other tools. As file names are not preserved, it's difficult to understand which of them were removed and it's also hard to tell how effective the final result should be. In the preview, we can see that some photos and videos are damaged. The documents can't be previewed. The program did manage to find some of the deleted data, but it lacks the quick scan feature. Deleted files are not marked in any way, all files are sorted into folders by type and it is difficult to find the ones you need. Also, file search takes quite a long time, taking into account the results demonstrated by its rivals is better to choose a different tool. One more program to test is Wondershare Recovered. One can see the test disk, but it can't identify its naming file system. Also, you can't choose scan type of this file system. When you try to open the disk, the full scan starts immediately. While scanning, the program uses signature search. Just as with the previous recovery tools, files are sorted by type. When the scan is over, we can see that the program managed to find the files, some photos are damaged, video previews are limited to 10 seconds, so it is hard to tell if the program can recover such files in full. In documents, you can only view the first page and the rest should be available only after you purchase the full version of this tool. In the end, we can say that this program does support ZFS, but some files get damaged, and it is difficult to evaluate the result properly as we can't see which of the files are the ones that have been deleted before the scan. The next one on the list is RSAVA. It can see the disk, but the format is unknown for this tool, as it can't identify the file system. You couldn't open the disk without scanning, so the deeper scan begins. In the end, the program found some files. It shows deleted photos in the root folder, and their contents can be previewed. Documents are not displayed. The videos that remained on the disk and the videos that we have removed could not be found, and there is not a single folder with photos. Videos are not displayed in preview. However, the disk structure is preserved, but one folder is still missing. That's a good result for a free tool, but you shouldn't rely on it too much, as most of the information was not recovered. For the second test, I'm going to erase the main VDAV label. Then I'll save the result to a disk image. It will be used in all recovery operations. On further tests, we'll only involve the programs that manage to recover all data and preserve the disk structure. And there, Hetman RAID Recovery and UFS Explorer. As to the others, we already know with more or less certainty what results should be expected. All right, let's start Hetman RAID Recovery. As you can see, even in this case, the program can identify the disk, its name and file system. Even the fast scan option is available. Finally, it shows the same result as in the previous test without erasing elements. All photos, documents and videos are displayed, and the deleted ones are marked accordingly with their names and disk structure preserved, and not a single file is damaged. Their contents can be viewed without any limitations, and it means you can be 100% sure that these files will be recovered in full. Let's try another candidate, UFS Explorer. There is no quick scan option either, so let's look for deleted data. The result is also similar to the previous test. The program has found the deleted files and marked them with a different color. However, previews are only available for photos. This is a serious disadvantage, as we don't know if the program can recover them in full, and to check it, all you can do is to buy the full version. That's why we can't be sure if the recovery works as expected. This is another drawback, because we cannot understand if they could be recovered in the end and if they are going to be damaged. Also, it's very inconvenient to know so little about your chances of recovery before you actually buy the tool. If we have a closer look at the photos, we can see that some photos are not displayed. Now, let's draw the bottom line. On the entire list of tested recovery tools, only two programs managed to find data with file names and disk structure preserved – Hetman RAID Recovery and UFS Explorer. However, UFS Explorer fails to display previews for documents and videos. Without saving the files, it is difficult to estimate if all of them can recover in full. And this is very inconvenient, because you have to buy the full version of the program to be able to save files and in the end, the files could be damaged and some documents or videos may never happen. On the other hand, Hetman RAID Recovery displays all files in the preview window and you can evaluate the program's effectiveness before actually paying for the full version license. The recovery process is very simple because of the convenient and intuitive interface that is easy to navigate even for beginners. This program lets you retain the folder structure and file names, which makes it easier to search for certain data and saves your time. The algorithm used in our product lets you recover data even if the entire structure of the file system is erased. And if the disk has at least some data left, Hetman RAID Recovery can restore it and display it to you due to using signature analysis. In addition, this tool supports recovery from raids of various levels, including RAID-Z, and it works with most file systems. It can also help you rebuild a damaged disk array and extract the lost information. And that is all for now. Hopefully, this video was useful. Remember to click the Like button and subscribe to our channel. To commence to ask questions, thank you for watching and good luck. While you're watching this video, civilians in Ukraine are dying from attacks in bombardments on the Russian Federation. Putin's insane regime has attacked a peaceful country in the very heart of Europe. Support the Ukrainian army by making a contribution to the font come back alive. 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