390:– Administration and Privileged Commands. "--make-bad-sector Deliberately create a bad sector (aka. "media error") on the disk. Note also that the --repair-sector option can be used to restore (any) bad sectors when they are no longer needed, including sectors that were genuinely bad (the drive will likely remap those to a fresh area on the media). --write-sector: This can be used to force a drive to repair a bad sector (media error)."
159:"pending". In the normal operation of a hard drive, the detection and remapping of bad sectors should take place in a manner transparent to the rest of the system and in advance before data is lost. There are two types of remapping by disk hardware: P-LIST (mapping during factory production tests) and G-LIST (mapping during consumer usage by disk microcode).
166:(SMART) information to tell how many sectors have been reallocated, and how many spare sectors the drive may still have. Because reads and writes from G-list sectors are automatically redirected (remapped) to spare sectors, it slows down drive access even if data in drive is defragmented. Once the G-list is filled up, the storage unit must be replaced.
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In a 2007 study, CERN observed 1.53 million hard drives from 30 models over 32 months and analyzed the drive read errors returned. They noted that 3.5% of drives developed "latent read error" (i.e. unreadable bad sector), and that a disk with a bad sector is more likely to develop more. Bad sectors
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When a sector is found to be bad or unstable by the firmware of a disk controller, a modern (post-1990) disk controller remaps the logical sector to a different physical sector. Typically, automatic remapping of sectors only happens when a sector is written to – failed reads remain marked
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do not have a bad-block avoidance feature at all. Software tools that look for bad blocks still have a use case: by issuing writes at detected bad sectors, one can expedite the remapping process, avoiding further attempts at reading the bad sector.
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On the other hand, sectors broken physically cannot be restored: writing would fail, forcing a remap. A new drive may start with some innocuous bad sectors due to manufacturing flaws. Larger patches occur throughout use, due to
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cluster spatially (in a 10–MB neighborhood) and temporally. Errors recovered by ECC, which are reported by enterprise drives (using the SCSI command set), also suggest a higher chance of a bad sector in the future.
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Compared to ATA, the SCSI command set allows finer-grained management of bad sectors. Users can read the G-LIST, control whether automatic remap is performed, and use a dedicated command
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Bad sectors can be "soft" (logical) or "hard" (hardware, physical), depending on what is making the sector inaccessible. In case of power loss, bit rot (more likely on
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With the advent of SMART-enabled disk controllers (see below), the burden of avoiding bad sectors more commonly falls to the disk. Some newer file systems such as
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Lakshmi N. Bairavasundaram; Garth R. Goodson; Shankar
Pasupathy; Jiri Schindler (June 2007). "An analysis of latent sector errors in disk drives".
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unit that is unreadable. Upon taking damage, all information stored on that sector is lost. When a bad sector is found and marked, the
197:(ECC) data. This can be used to verify bad sector support in disk utilities and forensic tools. For instance, to make sector 10 bad:
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contain provisions for sectors to be marked as bad, so that the operating system avoids them in the future. Disk diagnostic
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Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS), working draft revision 3f
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to manually remap if needed. The command set also provides a way to perform low-level format with
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to "flag" a sector as bad: the drive controller would not attempt to read, but fail immediately.
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This article is about a hard drive fault. For the ambient-noise music project, see
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can fix. This is a "soft" bad sector: writing over the corruption would succeed.
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can be used to create deliberate "soft" bad sectors by manipulating the sector
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command that works similarly. For newer drives, it can alternatively use
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276:"Hard vs Soft Bad Sectors in HDD: Different Causes and Solutions"
493:. San Diego, California, United States: ACM. pp. 289–300.
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447:, ANSI INCITS, pp. 198–213, 327–344, archived from
253:- a more serious form of damage to the hard disk platter
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will skip it in the future. Bad sectors are a threat to
138:) can actively look for bad sectors upon user request.
247:– bad sector protection on DVDs, used by Sony.
82:, wear-and-tear, physical shock, or dust intrusion.
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Self-Monitoring, Analysis, and
Reporting Technology
356:"badblocks - Can btrfs track / avoid bad blocks?"
16:Sector of a disk storage unit which is ureadable
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438:Stephens, Curtis E, ed. (11 December 2006),
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200:ATATOOL /BADECC:10 \\.\PhysicalDrive1
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309:"Question - should i rma my 980 pro"
102:Bad sectors may be detected by the
241:– a method of avoiding bad sectors
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400:Monitoring Hard Disks with SMART
360:Unix & Linux Stack Exchange
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293:Chris Hoffman (5 July 2017).
106:or the disk controller. Most
573:Solid-state computer storage
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568:Hard disk computer storage
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509:10.1145/1254882.1254917
212:WRITE_UNCORRECTABLE_EXT
162:Utilities can read the
338:"Bad Sector Remapping"
274:Zhang (2 March 2018).
551:Bad Blocks Definition
195:Error correction code
72:error correcting code
313:Tom's Hardware Forum
181:Manipulation methods
52:information security
468:. 15 September 2020
315:. 14 February 2023
280:Data Recovery Blog
87:solid-state drives
30:in computing is a
245:ARccOS Protection
208:--make-bad-sector
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32:disk sector
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258:References
251:Head crash
114:, such as
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28:bad sector
21:Bad Sector
495:CiteSeerX
421:PCMag.com
378:hdparm(8)
342:mjm.co.uk
233:Spiradisc
218:Frequency
132:badblocks
112:utilities
527:14164251
227:See also
189:program
93:Handling
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319:22 July
191:ATATool
187:Windows
62:Details
44:Windows
532:9 June
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388:Manual
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