Badblocks - Revision history

Leo at 20:06, 2 October 2022

2022-10-02T20:06:18Z

← Older revision		Revision as of 20:06, 2 October 2022
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	Use the {{code\|-n}} flag for a non-destructive test. A non-destructive test will store the sector value, test the sector, then restore the original sector value.		Use the {{code\|-n}} flag for a non-destructive test. A non-destructive test will store the sector value, test the sector, then restore the original sector value.

	There are 3 numbers that will be returned as 1/2/3 in ~~this order~~:		Use the <code>-b</code> option to specify the block sizes. This defaults to 1024 bytes. If you intend to use this on EXT filesystem creation, ensure this matches the filesystem block size by checking with <code>dumpe2fs /dev/sdX \| grep 'Block size'</code>.

			=== Understanding the output ===
			{{Highlight
			\| code = Checking for bad blocks in read-write mode
			From block 0 to 15630677
			Testing with pattern 0xaa: 20.32% done, 1:55 elapsed. (0/0/0 errors)
			\| lang = text
			}}
			There are 3 numbers that will be returned as <code>(1/2/3 errors)</code> in the last line. Each number represents:
	# number of read errors		# number of read errors
	# number of write errors		# number of write errors
	# number of corruption errors		# number of corruption errors

	~~The badblocks.txt~~ file that ~~gets created can then be used by {{code\|mkfs}} so that the filesystem can skip~~ over known bad ~~sectors like so:~~		=== Creating a filesystem around bad blocks ===
	~~{{highlight\|lang=terminal\|code=~~		Most filesystems can take a file containing a list of all bad blocks and create a filesystem that skips over these known bad locations.
	~~# mkfs~~.~~ext4 -l /tmp/badblocks.txt /dev/sda~~
	}}

	~~=== Creating a filesystem around bad blocks ===~~		For ext4, you can pass in the list of bad blocks with <code>-l</code>. You must however, make sure that the block size you used with <code>badblocks</code> matches what <code>mkfs</code> uses. As a result, unless you're sure what you're doing, you should just use the <code>-c</code> or <code>-cc</code> options with <code>mkfs.ext4</code>.{{highlight
	~~Most filesystems~~ can ~~take a file containing a~~ list of ~~all~~ bad blocks ~~and work around it~~. ~~However~~, unless you ~~know~~ what you're doing, ~~it's suggested that~~ you use the {{code\|-c~~}} option in~~ {{code\|mkfs.~~whatever}} instead because different filesystems may use different block sizes. The benefit of using~~ badblocks ~~is the fact testing is done with multiple passes rather than the one built into mkfs~~.		\| lang = terminal
			\| code = # mkfs.ext4 -l /tmp/badblocks.txt /dev/sda

	Eg:		## Alternatively, just have mkfs.ext4 check for badblocks for you. c=read only test, cc=read/write test
	{{highlight\|lang=terminal\|code=		# mkfs.ext4 -cc /dev/sda
			}}Other filesystems that take a list of bad blocks using <code>-l</code> include EXT2, EXT3, FAT. Here's another full example:{{highlight\|lang=terminal\|code=
	# fdisk /dev/sdb		# fdisk /dev/sdb
	## Make your desired partitions		## Make your desired partitions

Leo at 22:00, 14 June 2020

2020-06-14T22:00:47Z

← Older revision		Revision as of 22:00, 14 June 2020
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	== See Also ==		== See Also ==
	* https://wiki.archlinux.org/index.php/Badblocks		* https://wiki.archlinux.org/index.php/Badblocks


	{{Navbox Linux}}[[Category:Linux]]		{{Navbox Linux}}[[Category:Linux]]
			[[Category:LinuxUtilities]]

Leo: Text replacement - "Category:Linux{{Navbox Linux}}" to "{{Navbox Linux}}Category:Linux"

2019-09-01T06:21:34Z

Text replacement - "Category:Linux{{Navbox Linux}}" to "{{Navbox Linux}}Category:Linux"

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	[[Category:Linux]]~~{{Navbox Linux}}~~		{{Navbox Linux}}[[Category:Linux]]

Leo: Text replacement - "{{Navbox Linux}}{{Navbox Linux}}" to "{{Navbox Linux}}"

2019-09-01T05:11:14Z

Text replacement - "{{Navbox Linux}}{{Navbox Linux}}" to "{{Navbox Linux}}"

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	[[Category:Linux]]~~{{Navbox Linux}}~~{{Navbox Linux}}		[[Category:Linux]]{{Navbox Linux}}

Leo: Text replacement - "Category:Linux" to "Category:Linux{{Navbox Linux}}"

2019-09-01T05:09:12Z

Text replacement - "Category:Linux" to "Category:Linux{{Navbox Linux}}"

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	[[Category:Linux]]{{Navbox Linux}}		[[Category:Linux]]{{Navbox Linux}}{{Navbox Linux}}

Leo: recategorize

2019-09-01T02:24:10Z

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← Older revision		Revision as of 02:24, 1 September 2019
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	== See Also ==		== See Also ==
	* https://wiki.archlinux.org/index.php/Badblocks		* https://wiki.archlinux.org/index.php/Badblocks


			[[Category:Linux]]{{Navbox Linux}}

Leo: /* Creating a filesystem around bad blocks */

2017-08-10T17:59:23Z

Creating a filesystem around bad blocks

← Older revision		Revision as of 17:59, 10 August 2017
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	=== Creating a filesystem around bad blocks ===		=== Creating a filesystem around bad blocks ===
	Most filesystems can take a file containing a list of all bad blocks and work around it. However, it's suggested that you use the {{code\|-c}} option in {{code\|mkfs.whatever}} instead because different filesystems may use different block sizes.		Most filesystems can take a file containing a list of all bad blocks and work around it. However, unless you know what you're doing, it's suggested that you use the {{code\|-c}} option in {{code\|mkfs.whatever}} instead because different filesystems may use different block sizes. The benefit of using badblocks is the fact testing is done with multiple passes rather than the one built into mkfs.

	Eg:		Eg:

Leo: /* Creating a filesystem around bad blocks */

2017-08-10T17:54:13Z

Creating a filesystem around bad blocks

← Older revision		Revision as of 17:54, 10 August 2017
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	=== Creating a filesystem around bad blocks ===		=== Creating a filesystem around bad blocks ===
	Most filesystems can take a file containing a list of all bad blocks and work around it. ~~To do so~~, ~~create~~ the ~~partitions and then run badblocks against each partition, then create the filesystem~~.		Most filesystems can take a file containing a list of all bad blocks and work around it. However, it's suggested that you use the {{code\|-c}} option in {{code\|mkfs.whatever}} instead because different filesystems may use different block sizes.

	Eg:		Eg:

Leo: /* Creating a filesystem around bad blocks */

2017-08-10T17:52:20Z

Creating a filesystem around bad blocks

← Older revision		Revision as of 17:52, 10 August 2017
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	}}		}}

	In some cases, the bad blocks may be positioned such that the filesystem cannot be created. ~~If you really want to get the device working~~, ~~you~~ can ~~try~~ moving the partition ~~around so~~ that ~~the~~ bad blocks ~~don~~'~~t interfere with~~ the ~~filesystem~~.		In some cases, the bad blocks may be positioned such that the filesystem cannot be created. Depending on where these bad blocks are located, this can be worked around by resizing down the partition or moving the starting location of the partition.

			For instance, if every block past 40000 are bad, you will need to create a partition that is (40,000/1024) megabytes or smaller in order to avoid these bad blocks. We divide by 1024 because that's the default block size used by badblocks, unless otherwise specified by the {{code\|-b}} option.

	== Other Information ==		== Other Information ==

Leo at 17:40, 10 August 2017

2017-08-10T17:40:18Z

@@ Line 22: / Line 22: @@
 }}
-== Test Patterns ==
+=== Creating a filesystem around bad blocks ===
 The test that is done by default is to write to the disk in 4 passes, each with the following pattern:
 # 0xAA - 10101010