Custom Query (1438 matches)

smartd has knowledge of the state of all the hard drives in the system, and as such it is a perfect abstraction layer between the hardware and services or software that would make use of such information.

Unfortunately, although it is a daemon, it currently behaves in a cron-like fashion, by querying the HDD at specified intervals and optionally sending emails when a fault is detected.

My proposal is to add a Unix socket interface to smartd so that the last-checked HDD state and drive inventory can be queried from external software. I am proposing a simple query interface: 1-line command, 1-line response.

What smartd should provide on the socket:

• a hello, I am running message; smartd version string included
• a command to shut down
• a command to reload the configs
• a command to provide internal daemon statistics, like daemon runtime, etc

For the drive data that should also be:

• a command to enumerate the drives monitored by smartd
• a command to provide SMART variables for the specified drive (including SCSI/ATA specifics)

Optionally, these might make sense too:

• a command to get/change device settings (-g -s in smartctl)
• a command to deal with self-tests, SMART-GPT logs

To help users distinguish between SMART capabilities and Linux process capabilities I suggest the following changes:

in smartd.cpp:

replace Use capabilities. by Drop Linux process capabilities

in smartd.8.in:

replace Use capabilities(7). by Use libcap to drop Linux process capabilities(7).