missing hdparm -B setting during resume

[ceg]

Binary package hint: acpi-support

/etc/acpi/power.sh sets fixed hdparm values but gets called only when switching power supply.

Disk spin-down and head parking should not be activated without controlled disk idling. The regular uncoordinated logging or journaling activity may spin up the disks back up almost imediately after spinning down and lead to excessive load cycling.
(https://wiki.ubuntu.com/PowerManagement)

Since laptop drives may default to park quickly after resume hdparm -B255 should be set during resume. (hdparm -B255 does not set undefined value 255 but switches the drives apm feature off.) (Testing for the minimal value without head parking occurances may prevent overheating of hotty drives and be ok for desktop machines, too.)

Let laptop-mode-tools switch hdparm settings for harddisks on resume. (Even when laptop_mode kernel feature is not activated. (the default case))

laptop_mode *might* need to be called with "auto force" on resume events. (To reapply hdparm settings even though AC state has not changed.)

Package acpi-support:
Remove laptop_mode start/stop calls and hdparm stuff from power.sh
Remove ENABLE_LAPTOP_MODE setting from /etc/default/acpi-support. (And point to laptop-mode.conf for LM on battery, empty battery and AC.)

Package laptop-mode-tools:
Include scripts that call "/usr/bin/laptop_mode auto" in in /etc/acpi/ac.d, battery.d, resume.d and start.d. Then its the users choice to put scripts after or before the laptop-mode symlinks.
(Adapt the approach from the original laptop-mode-tools debian package to current ubuntu acpi-support)

(The current laptop-mode disk-idleing approach seems to be a left-over from the droped ubuntu-laptop-mode package config.)

[ceg (ceg)]

There is now an overview about the related bugs in the wiki.
https://wiki.ubuntu.com/PowerManagement#head-ab94c99627b86e9fbb29a09d3316178269c3e764

[ceg (ceg)]

In 9.10: /etc/acpi/power.sh rightly so does not mess with hdparm any more.

I can't test if hdparm -B is set correctly after a resume by another package, if not open new bug on that package.