Apple Fusion Drive, saving data when replacing the hard drive
Recently, there has been a sharp increase in the number of cases of irretrievable data loss associated with a lack of understanding of the features of Apple Fusion Drive technology.
The purpose of this note is to pay attention to these features and to warn users of Apple devices with Fusion Drive technology against actions leading to the destruction of information when replacing a hard disk.
The correct sequence of actions:
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The sequence leading to data loss:
Apparently, at the moment the life cycle of hard drives in a large number of Apple devices with Fusion Drive technology (further FD) is coming to an end. And users are massively turning to the appropriate service centers, where hard disks are replaced with serviceable ones.
Then many of them, independently or with the help of specialists, try to extract data from the old disk. And at this moment they face the “reverse side” of FD, which makes the complete recovery of information impossible.
In general, practice shows that employees of service centers do not always seek to delve into the features that must be considered to preserve customer data. Therefore, if you keep important information on the FD repository, it is useful to understand in general terms how it works.
FD is a combination of two drives, one of which is a solid-state SSD of small size, and the second is a regular hard drive (or, in the case of laptops, a laptop). In this case, the user sees such a device in the system as one logical volume with a total capacity equal to the sum of SSD and HDD capacities.
As you can already guess from the total volume, SSD is used directly for storing information, and not as a cache. In order to reduce the average access time, the operating system places the most requested part of the data on it. Thus, among other things, there is service information of file systems and frequently used user files.
Part of the data is placed on the SSD immediately, the other part is moved there gradually, automatically, as information on user activity accumulates. As a result, the contents of the least requested files appear on a slower hard disk.
When initialization, formatting and reinstallation of the operating system is performed after replacing the HDD, not only the most current user data is deleted on the SSD, but also the file system overhead, which is key to the integrity of the files remaining on the old HDD.
As a result, without the information contained on the SSD, from the replaced hard drive in most cases it is possible to recover only individual pieces of few meaningful files.
The purpose of this note is to pay attention to these features and to warn users of Apple devices with Fusion Drive technology against actions leading to the destruction of information when replacing a hard disk.
Briefly
The correct sequence of actions:
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- Save all important information. If the hard drive is out of order and it cannot be done on its own - contact an expert.
- Replacing the drive in a computer or laptop and then returning to operation.
The sequence leading to data loss:
- Replacing the disc and returning the device to operation.
- Attempt to copy the necessary files from the hard drive removed from the device.
Read more
Apparently, at the moment the life cycle of hard drives in a large number of Apple devices with Fusion Drive technology (further FD) is coming to an end. And users are massively turning to the appropriate service centers, where hard disks are replaced with serviceable ones.
Then many of them, independently or with the help of specialists, try to extract data from the old disk. And at this moment they face the “reverse side” of FD, which makes the complete recovery of information impossible.
In general, practice shows that employees of service centers do not always seek to delve into the features that must be considered to preserve customer data. Therefore, if you keep important information on the FD repository, it is useful to understand in general terms how it works.
FD is a combination of two drives, one of which is a solid-state SSD of small size, and the second is a regular hard drive (or, in the case of laptops, a laptop). In this case, the user sees such a device in the system as one logical volume with a total capacity equal to the sum of SSD and HDD capacities.
As you can already guess from the total volume, SSD is used directly for storing information, and not as a cache. In order to reduce the average access time, the operating system places the most requested part of the data on it. Thus, among other things, there is service information of file systems and frequently used user files.
Part of the data is placed on the SSD immediately, the other part is moved there gradually, automatically, as information on user activity accumulates. As a result, the contents of the least requested files appear on a slower hard disk.
When initialization, formatting and reinstallation of the operating system is performed after replacing the HDD, not only the most current user data is deleted on the SSD, but also the file system overhead, which is key to the integrity of the files remaining on the old HDD.
As a result, without the information contained on the SSD, from the replaced hard drive in most cases it is possible to recover only individual pieces of few meaningful files.
Options for action to help save data
- Backup.
- If the hard drive is healthy, but for some reason you want to replace it, first save all important files to another drive.
- If the hard drive fails and there is no current backup, bring the device to restore completely, without attempting to replace the hard drive and reinstall the system.
- If you still need to urgently return a laptop or computer in operation, save a sector copy of the SSD before replacing the hard drive.
Source: https://habr.com/ru/post/374509/
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