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datarecovery:bad_sectors [2019/02/19 09:47] – created niziakdatarecovery:bad_sectors [2020/12/16 13:19] (current) – niziak
Line 1: Line 1:
 +====== bad sectors ======
 +
 ====== SMART test ====== ====== SMART test ======
  
Line 19: Line 21:
  
 ====== Repair sector ====== ====== Repair sector ======
 +<code bash>
 +smartctl -a /dev/sdb
 +
 +SMART Self-test log structure revision number 1
 +Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
 +# 1  Short offline       Completed: read failure       90%     60539         974041815
 +# 2  Short offline       Completed without error       00%     60516         -
 +</code>
 +
 +<code bash>
 +#Try to read bad sector:
 +hdparm --read-sector 974041815 /dev/sdb
 +
 +/dev/sdb:
 +reading sector 974041815: SG_IO: bad/missing sense data, sb[]:  70 00 03 00 00 00 00 0a 40 51 e0 01 11 04 00 00 a0 d7 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 +succeeded
 +
 +hdparm --yes-i-know-what-i-am-doing --repair-sector 974041815  /dev/sdb
 +
 +# Test rest of disk:
 +smartctl -t select,974041815-max /dev/sdb
 +
 +smartctl -l selftest /dev/sdb
 +=== START OF READ SMART DATA SECTION ===
 +SMART Self-test log structure revision number 1
 +Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
 +# 1  Selective offline   Completed: read failure       90%     60550         974041843
 +# 2  Short offline       Completed: read failure       90%     60539         974041815
 +
 +hdparm --yes-i-know-what-i-am-doing --repair-sector 974041843  /dev/sdb
 +
 +# Test rest of disk:
 +smartctl -t select,974041815-max /dev/sdb
 +
 +</code>
 +
 +Ready script to automate above:
 +[[https://serverfault.com/questions/461203/how-to-use-hdparm-to-fix-a-pending-sector|How to use hdparm to fix a pending sector?]]
 +Fixed version:
 +<code bash>
 +#!/bin/bash -u
 +baddrive=/dev/sdb
 +badsect=974041815
 +while true; do
 +  echo Testing from LBA $badsect
 +  smartctl -t select,${badsect}-max ${baddrive} 2>&1 >> /dev/null
 +
 +  echo "Waiting for test to stop (each dot is 5 sec)"
 +  while [ "$(smartctl -a ${baddrive} | awk '/Self-test execution status:/ {print $5}')" = "249)" ]; do
 +    echo -n .
 +    sleep 5
 +  done
 +  echo
 +
 +  echo "Waiting for test to stop (each dot is 5 sec)"
 +  while [ "$(smartctl -l selftest ${baddrive} | awk '/^# 1/{print substr($5,1,9)}')" != "Completed" ]; do
 +    echo -n .
 +    sleep 5
 +  done
 +  echo
 +
 +  badsect=$(smartctl -l selftest ${baddrive} | awk '/# 1  Selective offline   Completed/ {print $10}')
 +  [ $badsect = "-" ] && exit 0
 +
 +  echo Attempting to fix sector $badsect on $baddrive
 +  hdparm --repair-sector ${badsect} --yes-i-know-what-i-am-doing $baddrive
 +  echo Continuning test
 +done
 +
 +</code>
 +
 +
 +For ZFS with RAIDZ filesytem, SCRUB is needed to replace bad data:
 +<code bash>
 +zpool scrub poolname
 +zpool status -v poolname
 +</code>
 +
  
 [[https://github.com/hradec/fix_smart_last_bad_sector]] [[https://github.com/hradec/fix_smart_last_bad_sector]]