What is Bad Blocks

Check out the following commands for BAD BLOCKS :-

Badblocks [options] device block-count.

    

    System administration command, Search device for bad blocks. You must specify the number of blocks on the device (block-count). e2fsck and mke2fs will invoke badblocks automatically when given the -c option.

Options:-

-b 

    blocksize

    Expect blocksize-byte blocks,

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-c   blocksize

    Test blocksize-byte blocks at a time. Default is 16,

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-f

    Force a read/write or nondestructive write test on a mounted device. Use only when /etc/mtab incorrectly reports a device as mounted.

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-i file

    Skip test of known bad blocks listed in file.

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-n

    Perform a nondestructive test by writing to each block & then reading back from it while preserving data,

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-o file

    Direct output to file,

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-p number

    Repeat search of device until no new bad blocks have been found in number passes, Default is 0.

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-s

    Show block numbers as they are checked,

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-t pattern

    Test blocks by reading and writing the specified pattern. You may specify pattern as a positive integer or as the word random, If you specifiy multiple patterns, badblocks will test all blocks with one pattern, and then test all blocks again with the next pattern. Read-only mode will accept only one pattern, It will not accept random.

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-v

    Verbose mode.

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-w

    Test by writing to each block and then reading back from it.

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