Retiring 8x2TB for 4x8TB + a 16TB moved the hottest drive to 40-41c,
exactly the old 40c ramp start, and the fan flipped 10<->15% every 30
seconds. The ramp is now 44-56c, which puts the drives back on the floor
with 19c of headroom to their 60c limit.
Adds the deadband from fan_speed.sh so the shelf does not chase every
degree once drives do climb into the ramp, with a downward-only periodic
settle so damping cannot leave it permanently loud.
selftest and disks no longer take the serial lock - they do not open the
port, and refusing to run them while the service is up is unhelpful.
The new tests caught a real bug: in `local a=$1 b=$a` bash expands the
right-hand sides before the locals exist, so the held value was silently
empty.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The shelf moved from iz-pve1 to iz-pve0, which has two SAS HBAs and an
internal backplane that is itself behind an expander. The default
"*-sas-exp*" glob matched all 17 drives there, so the shelf's fans would
have been set from the server's own drive temperatures.
PORT and DISK_GLOB are now overridable from the unit. Documents that the
host holding the shelf also needs the mirror-image DISK_EXCLUDE_PATTERN
in fan_speed.service - it was counting 17 disks until that was set.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
das_fanctl.sh reads drive temps via smartctl (falling back to the EMM
backplane sensors), interpolates a fan percentage, and re-sends _shutup
on a 5s keepalive so the shelf does not revert to full speed.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
