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查看syslog日志发现有硬盘提示扇区错误：

Dec 30 07:08:27 ubuntu-20 kernel: [34767.158065] blk_update_request: critical medium error, 
dev sda, sector 1729898440 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0

badblocks查看出错的扇区数量，-b指定每次扫描的区块大小，设置为和扇区大小一致，1729898440为日志提示出错的扇区位置，1729898499指定扫描扇区的终止位置，扫描后可以看到共有8个扇区出错。

badblocks -b 512 /dev/sda 1729898499 1729898440
1729898440
1729898441
1729898442
1729898443
1729898444
1729898445
1729898446
1729898447

写入修复坏掉的扇区，注意会丢失之前的数据，如果有坏道硬盘会自动重映射坏掉的扇区。

badblocks -b 512 -w /dev/sda 1729898447 1729898440

扫描整盘，-b指定每次扫描的块大小，如果用于扇区写入为512，文件系统隔离为4096，-s显示进度，-v详细输出。

badblocks -b 512 -s -v -o badblocks.log /dev/sdf

读取生成的坏块列表使用badblocks写测试能否修复或重映射扇区。

<?php
$list = file('badblocks.log');
$arr = array();
$i = 0;
$last = 0;
foreach ($list as $v) {
  $v = trim($v);
  if (!$v) {
    continue;
  }
  if (!$last) {
    $arr[$i][] = $v;
    $last = $v;
    continue;
  }
  if (($v - $last) == 1) {
    $arr[$i][] = $v;
  } else {
    $i++;
    $arr[$i][] = $v;
  }
  $last = $v;
}
foreach ($arr as $vv) {
  if (count($vv) > 1) {
    $start = reset($vv);
    $end = end($vv);
  } else {
    $start = reset($vv);
    $end = reset($vv);
  }
  echo '/usr/sbin/badblocks -w -s -v /dev/sdf '."$end $start".PHP_EOL;
  shell_exec('/usr/sbin/badblocks -w -s -v /dev/sdf '."$end $start");
}

也可使用hdparm和dd写扇区：

hdparm --write-sector 77610960 --yes-i-know-what-i-am-doing /dev/sdf
dd if=/dev/zero of=/dev/sdf bs=512 seek=77610960 count=1

或重写整个硬盘：

dd iflag=fullblock oflag=direct conv=noerror,notrunc if=/dev/zero of=/dev/sdf bs=1M

对于不能修复的坏块让文件系统隔离，未经验证。

e2fsck -l badblocks.log /dev/sdf
mkfs -l badblocks.log /dev/sdf

参考：
https://zhuanlan.zhihu.com/p/31899347
https://www.linuxcool.com/badblocks
https://lug.ustc.edu.cn/wiki/linux_digest/badblocks/
https://tomjamescn.github.io/post/2019-06-16-repair-hard-disk-with-bad-sectors/
https://unix.stackexchange.com/questions/229354/how-to-ignore-write-errors-while-zeroing-a-disk/229362
https://superuser.com/questions/1322780/fix-or-reallocate-a-bad-sector
https://askubuntu.com/questions/751134/problems-restoring-damaged-sectors-on-hdd