NAME

badblocks - 查詢設備的壞區塊  

語法（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 被用來在設備（通常是磁盤分區）中檢測壞區塊。 device 參數是設備的名字(例如 /dev/hdc1). blocks-count 參數是設備上總的區塊數目；如果沒有指定這個參數，默認值就是設備的容量大小。 start-block參數是一個可選參數，它指定從多少區塊號開始進行檢測。因此，檢測允許從磁盤的中間部分開始。  

選項（OPTIONS）

-b block-size

以字節為單位，指定區塊的大小。

-c number of blocks

每一次檢測區塊的數目。默認值是16。增加這個數目可以增加檢測 壞塊 的效率可同時也會增加內存的耗費。 Badblocks 命令在只讀模式下需要花費與每一次檢測的區塊相同數目的內存容量。在讀寫模式下，這個比例是兩倍而在非破壞性的讀寫模式下，這個比例是三倍。如果你將參數“num-of-blocks”設置太大的話， badblocks 將會在分派緩存時會因為一個內存溢出錯誤而立即退出。當然如果你在非破壞性的讀寫模式下將該值設置得過低，那么在一個不穩定的磁盤上的有問題的區塊也許會因為磁盤的磁道緩沖的作用而不被檢測出來。

-f

正常情況下，badblocks命令不會在一個已經激活的設備上讀寫模式或者是非破壞性的讀寫模式的檢測，因為這可能會導致系統的崩潰。使用 -f 標志可以使這種情況強制執行，但是最好不要在正常的情況下使用它。如果/etc/mtab文件發生了錯誤，而設備實際上并沒有被激活的時候，這個參數才會是安全的。

-i input_file

讀入一個已知的壞塊列表。 Badblocks 命令將會跳過對這些已知是壞塊的區塊檢查。如果 input_file 參數是“-”，則列表從標準輸入讀入。在這個列表中列舉出的區塊也會在 新的 壞道記錄文件或者壞道記錄輸出時被忽略掉。 dumpe2fs(8) 的 -b 選項能夠在一個已有的文件系統中得到被標記為壞塊的列表，而且已經做成了符合這個選項的格式。

-o output_file

將壞塊的列表寫到指定的文件中。如果沒有這個選項， badblocks 命令會在標準輸出中輸出這個列表。其格式是與 e2fsck(8) 或者 mke2fs(8). 的 -l 選項的要求相適應的。

-p num_passes

重復的掃描磁盤，直到重復“num_passes”遍磁盤掃描后也沒有發現新的區塊后結束。默認值是0。表示 badblocks 命令成功執行一遍掃描后就會結束。

-n

使用非破壞性的讀寫模式。默認值是非破壞性的只讀模式測試。這個選項不能與 -w 選項一起使用，因為它們是互斥的。

-s

通過輸出正在被檢測的區塊的號碼以表示檢測進程。

-v

混雜模式檢測。

-w

使用寫模式測試。通過使用這個選項 badblocks 通過往每個區塊上寫入一些特定的字符（0xaa，0x55，0xff，0x00），讀出來后再比較其內容，決定是否為壞塊。這個選項不能與 -n 選項一起使用，因為它們是互斥的。

警告（WARNING）

千萬不要將 -w 選項用在一個已經包含了文件系統的設備上。這個選項會刪除掉原有的數據！如果你想要在已經有文件系統的設備上執行讀寫模式檢測，請使用 -n 選項。雖然慢點，可是它能夠保護你的數據不受傷害。  

作者（AUTHOR）

badblocks 作者是Remy Card <Remy.Card@linux.org>. 維護人 Theodore Ts'o <tytso@alum.mit.edu>. 非破壞性的讀寫模式測試由David Beattie <dbeattie@softhome.net>進行.  

有效資源（AVAILABILITY）

badblocks 是e2fsprogs套件的一部分。能夠從支持匿名訪問的ftp站點tsx-11.mit.edu的/pub/linux/packages/ext2fs目錄下取得。  

另外請參考

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)