Avoid data loss. Don’t be careless about bad blocks in solid-state drives.

Solid-state drives have captured more and more users with their extremely fast read and write speeds. However, like all storage devices, solid-state drives also have some problems that need attention. One of the potential problems is bad blocks (BadBlock). We often say that hard drives are valuable and data is priceless. We need to understand the bad blocks of SSD in order to better avoid the problem of data loss.

Bad blocks, as the name suggests, refer to flash memory blocks in solid-state drives that cannot be read or written normally. These blocks are damaged due to various reasons when leaving the factory or during use, causing data to be unable to be stored or read correctly, thus affecting the normal use of users.

Bad blocks generally occur in two situations. One is in the manufacturing process, which already exists before the solid-state drive leaves the factory. It is usually a defect produced during wafer inspection, cutting, packaging and other processes. The solid-state drive manufacturer will use special testing equipment and software to identify and mark these bad blocks to ensure that they will not be used for data storage.

The other is during use. As the use time of the solid-state drive increases, some originally normal flash memory blocks may not work properly due to wear and tear. This is an inevitable loss phenomenon during the use of the solid-state drive.

It should be noted that there is another situation during use, that is, unexpected power outages, vibrations, etc. cause the data to not complete the writing operation in the designated block, resulting in the data being unable to be read, or an error in executing the read command, which will also cause the main control to judge it as a bad block, but in fact this area may be normal. We will not discuss this small probability event too much. Everyone knows that this situation exists.

In order to effectively manage bad blocks, the SSD master will create a bad block table (BadBlockTable, BBT). The bad block table is like a "blacklist" that records the location information of bad blocks that have been detected. When the master needs to write or read data, it will first refer to the bad block table to avoid these areas that cannot work properly to ensure the accuracy and integrity of the data.

The bad block table will be saved in a separate area, but in order to prevent the bad block table itself from being lost due to unexpected circumstances (such as flash memory damage), the main control chip usually backs up the bad block table and restores it when needed.

SSDs usually have a certain percentage of spare space reserved at the factory. When a bad block is detected, the hard disk's controller will automatically remap the data to spare space to ensure normal storage and reading of data.

During daily use, it is recommended that you equip your computer with a power supply with sufficient rated power to ensure stable power supply. Try to avoid bumps and bumps when using the computer. In addition, try to leave more than 10% of the remaining space on the SSD. When the remaining space is seriously insufficient, avoid frequent reading and writing, especially when used as a system disk, to have a better usage experience.

However, in order to prevent data loss caused by bad blocks, it is still crucial to back up important data regularly. If your SSD has problems such as reduced reading and writing speed, slow response, etc., you can use third-party software to check various parameters of the SSD. If there are too many bad blocks, you need to back up important data in time and replace the hard drive to ensure data security.