Disk Surface Test Bad Sectors
Latisha Gervase
With the disk coming into increasing use, bad sectors will appear, and there will be more and more. The data stored in a bad sector may be corrupted or lost. How to know if there are bad sectors in the hard drive? You can make a surface test with a well-designed disk surface test tool.
A surface test is a scan of a hard drive (HDD or SSD) for bad sectors. Disk surface test does what it implies - it scans the hard disk surface, checks bad sectors, and marks bad sectors so that the computer knows they will not be used in the future.
EaseUS Partition Master comes to help with its Surface Test feature. It can identify bad sectors by reviewing the hard drive. When it finds bad sectors, it will mark those sectors with red color so that the system knows not to use them.
EaseUS Partition Master provides the simplest solution for performing a hard disk surface test in one click. This all-in-one disk management tool makes it easy to partition HDD/SSD to improve system performance.
Disk surface testing is the most effective way to detect bad sectors on a disk. In this article, EaseUS Partition Master can scan and locate bad sectors on a disk. If your disk has bad sectors, it will mark them in red and diagnose your disk condition. If this article helps you, don't forget to share this article and let more users know about the EaseUS surface test software.
Yes, but bad sectors tend to increase over time, potentially leading to more data loss and eventual drive failure. So you can continue using a hard drive with a few bad sectors, but it's not recommended for long-term use or storing important data.
The only option I see for a surface scan is /r which scans the surface but also attempts recovery of bad sectors. If you suspect a bad drive, I wouldn't always necessarily want to attempt recovery, just check the surface if there's any bad sectors, attempt a backup, then try to repair.
Checks the file system and file system metadata of a volume forlogical and physical errors. If used without parameters, chkdskdisplays only the status of the volume and does not fix any errors. Ifused with the /f, /r, /x, or /b parameters, it fixes errors on thevolume.Microsoft Documentation
By using this test, the surface of the hard disk can be examined with different methods. Some of thesemethods are safe for the stored data but others are destructive: the stored information are permanently erasedduring the test operation.
First it is required to select the hard disk and the test type to be started. The detailed description ofthe test are displayed upon selection, and the software displays how the test affects stored data. It isstrongly recommended to read these information carefully before starting the test.It is possible to use the "Multiple disk drives" button to select more disks to be tested at the same time using the same test method, options and settings. The amount of disks to be tested is not limited (just the overall system performance/resources may limit them).
- READ Test - Reads the disk surface to verify if all sectors are accessible and readable.
The test is safe, it does not affect stored data.
Disk problems may remain hidden and revealed disk issues are NOT fixed (like with ScanDisk).
- WRITE test - Overwrites the disk surface with configurable pattern. Forces the analysis of any weak sectors and verifies any hidden problems and fixes them by reallocation of bad sectors (this is drive regeneration).
Enables better use of the disk as after the test the spare area will be used instead of any problematic sectors.
Note: on the Configuration page, it is possible to configure the pattern to be written bythe write test. By default, Hard Disk Sentinelwrites zeroes (00 bytes) but it is possible to specify that all sectors should contain the sector numbers (may be useful in later data recovery) or even random data. Also it is possible to specify any byte/byte sequence as overwritepattern. For example entering ABC in the byte/byte sequence field will cause that all sectors will contain ABC stringrepeating. In this option, it is possible to enter hex sequence, for example 0x99 0x88 0x77 to write such bytes. It is also possible to specify FILE=existing file name, then the contents of the file will be used as overwrite pattern.
- WRITE + read test (Pro version only) - Overwrites the disk surface with configurable pattern and then reads back sector contents, to verify if they are accessible and consistent. Forces the analysis of any weak sectors and verifies any hidden problems and fixes them by reallocation of bad sectors (this is drive regeneration).
Enables better use of the disk as after the test the spare area will be used instead of any problematic sectors.
- Read + WRITE + read test (refresh data area) (Pro version only) - Reads stored data from each blocks, writes back the contents and finally reads the information and compare with original contents. By the extensive test, an additional write cycle is used before writing back the contents to improve the efficiency of the error correction (drive regeneration).
The operation is usually safe for the stored information but data loss may occur if the system is not stable and/or upon power failure, overclocking, memory/power supply/cable problems and other factors.
The test can be used to refresh the data area of the storage device, without the need of complete erase but it is still recommended to backup important data before this test.
- Reinitialize disk surface (Pro version only) - Overwrites the disk surface with special initialization pattern to restore the sectors to default (empty) status and reads back sector contents, to verify if they are accessible and consistent. Forces the analysis of any weak sectors and verifies any hidden problems and fixes them by reallocation of bad sectors (this is drive regeneration).
Enables better use of the disk as after the test the spare area will be used instead of any problematic sectors.
Very intensive and time-consuming test, especially if the level (the number of overwrite cycles) is set to higher value.
The simple version of this test is usually (incorrectly) called as low level format by other tools. It can be effectively used to permanently destruct stored information (Navso P-5239-26 standard data destruction).
- Disk Repair (Pro version only) - Reads the disk surface to verify if all sectors are readable and forces the disk drive to repair any problematic (pending, weak) sectors: restore the status to good or reallocate (replace from spare area) if required to prevent further use of the original sector.
The test is safe for stored data and the damaged file(s) will be readable, however file fragment(s) on damaged sectors may be corrupted. File(s) on the affected repaired sectors are listed when the test completed.
The test is best to be used to repair drives with weak sector(s) without the need of complete backup (and use of the Reinitialize disk surface test) and works on both system and secondary drives too. For more information, please check: Hard disk case: weak sectors
In general, it is possible to configure the order of blocks to be tested and optionally the repeat countcan be specified (so the software runs the same test on the disk two or more times) and it is possible tounmount all logical volumes (partitions) during the test. The latter is strongly recommended to preventother software and the operating system from accessing the disk during test. System drive (containingthe operating system, the root folder of the user or the swapfile of Windows) cannot be locked this way.Because of the actual system running, only read test (which does not affect stored data) can be used on a system drive.
The software divides the data area to 10000 blocks, this is the surface map of the disk. When any block isclicked by the mouse, the contents of the sector under the selected block are displayed. This way it ispossible to inspect the stored data and/or the written data after performing a write test. It is possible toexamine the sector contents (and load back the results of a previously saved test) without starting a test by clicking the View button. This is safe for the stored data on the disk.
During the tests, Hard Disk Sentinel verifies the integrity of each sectors under the displayed blocks.If the block is accessible and can be processed without errors, they are shown by green color. Darker greencolor means that the sectors are slower and harder to process (read or write depending on the test type) but they are still good. Having some (especially random) darker green blocks are completely acceptable unless they form a continuous, larger area (especially with yellow/red blocks near). The software filters out theeffect of slower transfer times at the end of the disks. If sectors are harder to access and can be processedonly after one or more retries, then the blocks are damaged but repaired, the software shows the corresponding blocks with yellow. Redcolor means that the block of sectors cannot be processed (read or written - according the selected test).Further WRITE test may be required to force the drive to reallocate the problematic sector(s) in the block.
In case of damaged or bad blocks found, it is recommended to examine the whole data surface with one or moreWRITE test(s). During write tests, the software forces the hard disk to verify the status of the sectors on the surfaceand re-allocate them to the spare area. This way the original (bad) sector will not be used and all furtherread and write operations are redirected to the spare area. This is called regeneration. The resultinghard disk functions better, it is even possible that on following tests it shows only good (green) blocksbecause the bad sectors are no longer used. The side effect of regeneration is that the health of the drivemay decrease because more and more problems are revealed. So regeneration usually does not improvethe health (except if weak sectors were found and their status if stabilized).
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