The Linux runtime power management (RPM) provides everything necessary to put unused disks to sleep and wake them up when required.
If properly configured this can save energy in SOHO environments where disks often idle in the night and during non office hours.
However, a major drawback when used with ZFS pool disks is the large latency until a sleeping zpool becomes available.
The zpool disks are not resumed in parallel which can lead to latencies of tens of seconds to minutes for larger pools.
For everybody interested to give RPM a try in combination with ZFS, zolspinup is a systemd service that can configure the RPM parameters on startup and spin-up the zpool disks in parallel.
The service executable can also be used to list the current RPM parameters and status of zpool disks when called with the name rpmstat.
If properly configured this can save energy in SOHO environments where disks often idle in the night and during non office hours.
However, a major drawback when used with ZFS pool disks is the large latency until a sleeping zpool becomes available.
The zpool disks are not resumed in parallel which can lead to latencies of tens of seconds to minutes for larger pools.
For everybody interested to give RPM a try in combination with ZFS, zolspinup is a systemd service that can configure the RPM parameters on startup and spin-up the zpool disks in parallel.
The service executable can also be used to list the current RPM parameters and status of zpool disks when called with the name rpmstat.