What Is smartd?
smartd stands for SMART Disk Monitoring Daemon. It is part of the smartmontools package and continuously monitors the SMART (Self-Monitoring, Analysis and Reporting Technology) system built into modern hard drives and SSDs.
SMART helps detect and report early warning signs of disk failure. By monitoring these indicators, smartd allows administrators to take preventive action before data loss occurs.
smartd supports:
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SATA and ATA disks
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SCSI disks
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Many SSDs and NVMe drives (limited attributes)
How SMART Works
SMART tracks several health indicators such as:
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Reallocated sectors
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Read and write errors
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Temperature
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Power-on hours
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Pending sector counts
When these values exceed safe thresholds, smartd can generate warnings via system logs or email notifications.
smartmontools Project
smartd is maintained as part of the smartmontools open-source project.
Key Contributors
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Bruce Allen – Project initiator
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Christian Franke – Lead developer and maintainer
The project is actively maintained and widely used across Linux, BSD, macOS, and Windows.
Project site:
https://sourceforge.net/projects/smartmontools/
Installing smartmontools
On Debian / Ubuntu
On RHEL / CentOS / Rocky / AlmaLinux
SMARTD Binary Path
Check if a Disk Supports SMART
First, identify your disk:
Then run:
| smartctl -i /dev/sda
If the disk supports SMART, you will see:
Enable and Manage smartd (systemd)
Enable smartd at boot
Start smartd
Stop smartd
Logging and Configuration
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Default log location:
(or journalctl on systemd systems)
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Configuration file:
smartd checks disk health approximately every 30 minutes by default. This interval can be customized in the configuration file.
Checking Disk Health Manually
Overall SMART health status
View vendor-specific SMART attributes
Sample smartd.conf Entries
These options:
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Enable all SMART checks
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Ignore selected attributes
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Schedule self-tests
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Send email alerts
Force smartd to Check Disk Health
The superuser can force an immediate check:
or
Advantages of smartd
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Continuous disk health monitoring
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Early warning of potential failures
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Email and log-based alerts
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Works with most modern storage devices
Limitations of SMART
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SMART cannot predict all failures
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Sudden electronic or mechanical failures may occur without warning
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SMART should be used alongside regular backups, not as a replacement
References
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smartd man page
If you require help, contact SupportPRO Server Admin
