NAME
badblocks - 查询设备的坏区块
语法（SYNPSIS）
badblocks [ -svwnf ] [ -b block-size ] [ -c blocks_at_once ] [ -i input_file ] [ -o output_file ] [ -p num_passes ] device [ blocks-count ] [ start-block ]
（描述）DESCRIPTION
badblocks 被用来在设备（通常是磁盘分区）中检测坏区块。 device 参数是设备的名字(例如 /dev/hdc1). blocks-count 参数是设备上总的区块数目；如果没有指定这个参数，默认值就是设备的容量大小。 start-block参数是一个可选参数，它指定从多少区块号开始进行检测。因此，检测允许从磁盘的中间部分开始。
选项（OPTIONS）
- -b block-size
- 以字节为单位，指定区块的大小。
- -c number of blocks
- 每一次检测区块的数目。默认值是16。增加这个数目可以增加检测 坏块 的效率可同时也会增加内存的耗费。 Badblocks 命令在只读模式下需要花费与每一次检测的区块相同数目的内存容量。在读写模式下，这个比例是两倍而在非破坏性的读写模式下，这个比例是三倍。如果你将参数“num-of-blocks”设置太大的话， badblocks 将会在分派缓存时会因为一个内存溢出错误而立即退出。当然如果你在非破坏性的读写模式下将该值设置得过低，那么在一个不稳定的磁盘上的有问题的区块也许会因为磁盘的磁道缓冲的作用而不被检测出来。
- -f
- 正常情况下，badblocks命令不会在一个已经激活的设备上读写模式或者是非破坏性的读写模式的检测，因为这可能会导致系统的崩溃。使用 -f 标志可以使这种情况强制执行，但是最好不要在正常的情况下使用它。如果/etc/mtab文件发生了错误，而设备实际上并没有被激活的时候，这个参数才会是安全的。
- -i input_file
- 读入一个已知的坏块列表。 Badblocks 命令将会跳过对这些已知是坏块的区块检查。如果 input_file 参数是“-”，则列表从标准输入读入。在这个列表中列举出的区块也会在 新的 坏道记录文件或者坏道记录输出时被忽略掉。 dumpe2fs(8) 的 -b 选项能够在一个已有的文件系统中得到被标记为坏块的列表，而且已经做成了符合这个选项的格式。
- -o output_file
- 将坏块的列表写到指定的文件中。如果没有这个选项， badblocks 命令会在标准输出中输出这个列表。其格式是与 e2fsck(8) 或者 mke2fs(8). 的 -l 选项的要求相适应的。
- -p num_passes
- 重复的扫描磁盘，直到重复“num_passes”遍磁盘扫描后也没有发现新的区块后结束。默认值是0。表示 badblocks 命令成功执行一遍扫描后就会结束。
- -n
- 使用非破坏性的读写模式。默认值是非破坏性的只读模式测试。这个选项不能与 -w 选项一起使用，因为它们是互斥的。
- -s
- 通过输出正在被检测的区块的号码以表示检测进程。
- -v
- 混杂模式检测。
- -w
- 使用写模式测试。通过使用这个选项 badblocks 通过往每个区块上写入一些特定的字符（0xaa，0x55，0xff，0x00），读出来后再比较其内容，决定是否为坏块。这个选项不能与 -n 选项一起使用，因为它们是互斥的。
警告（WARNING）
千万不要将 -w 选项用在一个已经包含了文件系统的设备上。这个选项会删除掉原有的数据！如果你想要在已经有文件系统的设备上执行读写模式检测，请使用 -n 选项。虽然慢点，可是它能够保护你的数据不受伤害。
作者（AUTHOR）
badblocks 作者是Remy Card <Remy.Card@linux.org>. 维护人 Theodore Ts'o <tytso@alum.mit.edu>. 非破坏性的读写模式测试由David Beattie <dbeattie@softhome.net>进行.
有效资源（AVAILABILITY）
badblocks 是e2fsprogs套件的一部分。能够从支持匿名访问的ftp站点tsx-11.mit.edu的/pub/linux/packages/ext2fs目录下取得。
另外请参考
e2fsck(8), mke2fs(8)
#p#
NAME
badblocks - search a device for bad blocks
SYNOPSIS
badblocks [ -svwnf ] [ -b block-size ] [ -c blocks_at_once ] [ -i input_file ] [ -o output_file ] [ -p num_passes ] [ -t test_pattern ] device [ last-block ] [ start-block ]
DESCRIPTION
badblocks is used to search for bad blocks on a device (usually a disk partition). device is the special file corresponding to the device (e.g /dev/hdc1). last-block is the last block to be checked; if it is not specified, the last block on the device is used as a default. start-block is an optional parameter specifying the starting block number for the test, which allows the testing to start in the middle of the disk. If it is not specified the first block on the disk is used as a default.
Important note: If the output of badblocks is going to be fed to the e2fsck or mke2fs programs, it is important that the block size is properly specified, since the block numbers which are generated are very dependent on the block size in use. For this reason, it is strongly recommended that users not run badblocks directly, but rather use the -c option of the e2fsck and mke2fs programs.
OPTIONS
- -b block-size
- Specify the size of blocks in bytes.
- -c number of blocks
- is the number of blocks which are tested at a time. The default is 64.
- -f
- Normally, badblocks will refuse to do a read/write or a non-destructive test on a device which is mounted, since either can cause the system to potentially crash and/or damage the filesystem even if it is mounted read-only. This can be overriden using the -f flag, but should almost never be used --- if you think you're smarter than the badblocks program, you almost certainly aren't. The only time when this option might be safe to use is if the /etc/mtab file is incorrect, and the device really isn't mounted.
- -i input_file
- Read a list of already existing known bad blocks. Badblocks will skip testing these blocks since they are known to be bad. If input_file is specified as "-", the list will be read from the standard input. Blocks listed in this list will be omitted from the list of new bad blocks produced on the standard output or in the output file. The -b option of dumpe2fs(8) can be used to retrieve the list of blocks currently marked bad on an existing filesystem, in a format suitable for use with this option.
- -o output_file
- Write the list of bad blocks to the specified file. Without this option, badblocks displays the list on its standard output. The format of this file is suitable for use by the -l option in e2fsck(8) or mke2fs(8).
- -p num_passes
- Repeat scanning the disk until there are no new blocks discovered in num_passes consecutive scans of the disk. Default is 0, meaning badblocks will exit after the first pass.
- -t test_pattern
- Specify a test pattern to be read (and written) to disk blocks. The test_pattern may either be a numeric value between 0 and ULONG_MAX-1 inclusive, or the word "random", which specifies that the block should be filled with a random bit pattern. For read/write (-w) and non-destructive (-n) modes, one or more test patterns may be specified by specifiying the -t option for each test pattern desired. For read-only mode only a single pattern may be specified and it may not be "random". Read-only testing with a pattern assumes that the specified pattern has previously been written to the disk - if not, large numbers of blocks will fail verification. If multiple patterns are specified then all blocks will be tested with an one pattern before proceeding to the next pattern.
- -n
- Use non-destructive read-write mode. By default only a non-destructive read-only test is done. This option must not be combined with the -w option, as they are mutually exclusive.
- -s
- Show the progress of the scan by writing out the block numbers as they are checked.
- -v
- Verbose mode.
- -w
- Use write-mode test. With this option, badblocks scans for bad blocks by writing some patterns (0xaa, 0x55, 0xff, 0x00) on every block of the device, reading every block and comparing the contents. This option may not be combined with the -n option, as they are mutually exclusive.
WARNING
Never use the -w option on an device containing an existing file system. This option erases data! If you want to do write-mode testing on an existing file system, use the -n option instead. It is slower, but it will preserve your data.
AUTHOR
badblocks was written by Remy Card <Remy.Card@linux.org>. Current maintainer is Theodore Ts'o <tytso@alum.mit.edu>. Non-destructive read/write test implemented by David Beattie <dbeattie@softhome.net>.
AVAILABILITY
badblocks is part of the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.
SEE ALSO
e2fsck(8), mke2fs(8)
