Question: I have a disk in a two-disk software RAID-1 for which recently an “offline uncorrectable sector” appeared in the SMART status.
198 Offline_Uncorrectable ?0x0030 ?200 ?200 ?000 ?Old_age ?Offline ?- ?1
This apparently is only a sign of imminent disk failure if it occurs increasingly frequently (and since the drive is mirrored, there is no great risk of real data loss either). At the time, a self test also failed at some point and smartd sent me an email to notify me of this as it of course should do.
However, writing to the damaged sector usually causes the disk to use one of its spare sectors instead which it apparently did because since I dded over the disk, all self-tests ran through just fine. And badblocks also found no reason to complain.
Num ?Test_Description ?Status ??Remaining ?LifeTime(hours) ?LBA_of_first_error[…]# 5 ?Extended offline ?Completed without error ?00% ?5559 ?-# 6 ?Short offline ?Completed without error ?00% ?5540 ?-# 7 ?Short offline ?Completed: read failure ?90% ?5524 ?63273368
The number of faulty sectors didn’t decrease though which it shouldn’t, really, since the broken sector’s still there, albeit unused. However, smartd continues to send me emails every night:
The following warning/error was logged by the smartd daemon:Device: /dev/sda [SAT], 1 Offline uncorrectable sectors
This is extremely annoying obviously and numbs my healthy panic reflex to smartd mails.
The disk is a Western Digital WD20EARS and the smartd version is 5.41 2011-06-09 r3365.
Answer: On a some disks, you might have to resort to -U 198+ (or -U + ?) in the config file.
Please be careful. ?If you are not the original asker, read through the whole question carefully. ?If you use this on a disk which does not need it, it will suppress entirely valid warnings.
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If ?+? ?is specified, a report is only printed if the number of sec� ?tors has increased since the last check ?cycle. ?Some ?disks ?do ?not ?reset ?this attribute when a bad sector is reallocated. ?See also ?-v ?198,increasing? below.
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For example, suppose you are using the default configuration in smartd.conf. ?In that case, there are many comments in the file, but the only non-comment line is here:
# The word DEVICESCAN will cause any remaining lines in this# configuration file to be ignored: it tells smartd to scan for all# ATA and SCSI devices. ?DEVICESCAN may be followed by any of the# Directives listed below, which will be applied to all devices that# are found. ?Most users should comment out DEVICESCAN and explicitly# list the devices that they wish to monitor.DEVICESCAN
Add the option to the end of the line:
DEVICESCAN -U 198+