smartdでエラーメッセージを受け取ったときの応急対応

grep -i "smartd" /var/log/messages | tail
Xxx xx 05:09:05 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 05:39:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 06:09:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 06:39:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 07:09:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 07:39:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 08:09:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 08:39:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 09:09:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 09:39:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors
Xxx xx 10:09:04 nemonemo-server smartd[xxxx]: Device: /dev/sdz, 1 Currently unreadable (pending) sectors

以下の記事を参考にsector errorを修復を試みる。

smartd での sector error 復活作業 | ni kvel

# smartctl /dev/sdz --log=selftest
smartctl version x.xx Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== 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  Short offline       Completed: read failure       10%     19935         1043624
# 2  Extended offline    Completed without error       00%     18472         -
# 3  Short offline       Completed without error       00%     18469         -
# 4  Extended offline    Completed without error       00%     18447         -
# 5  Extended offline    Completed without error       00%     16669         -
# 6  Short offline       Completed without error       00%     16645         -
# 7  Extended offline    Completed without error       00%     13278         -
# 8  Short offline       Completed without error       00%     12081         -

以下の公式からseek箇所を算出。

        b = (int)((L-S)*512/B)
        where:
        b = File System block number
        B = File system block size in bytes
        L = LBA of bad sector
        S = Starting sector of partition as shown by fdisk -lu
        and (int) denotes the integer part.

S = 0、B = 4096、L = 1043624を公式に代入。

b = (int)(1043624 * 512 / 4096) = (int) 130453 (小数点以下切捨)

となった。該当箇所をddでゼロで埋める。

# dd if=/dev/zero of=/dev/sdz bs=4096 count=1 seek=130453
    1+0 records in
    1+0 records out
    4096 bytes (4.1 kB) copied, 0.000270448 s, 43.8 MB/s

そして、正常にもどったかどうかチェック！

# smartctl –-test=long /dev/sdz

･･･数時間経過後。

# smartctl –-log=selftest /dev/sdz
smartctl version x.xx Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== 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  Extended offline    Completed without error       00%     19937         -
# 2  Short offline       Completed: read failure       10%     19935         1043624
# 3  Extended offline    Completed without error       00%     18472         -
# 4  Short offline       Completed without error       00%     18469         -
# 5  Extended offline    Completed without error       00%     18447         -
# 6  Extended offline    Completed without error       00%     16669         -
# 7  Short offline       Completed without error       00%     16645         -
# 8  Extended offline    Completed without error       00%     13278         -
# 9  Short offline       Completed without error       00%     12081         -

以上。