hard disk parks regularly after resume - hdparm -B 254 has no effect
Binary package hint: pm-utils
After each suspend/resume cycle on my Dell XPS M1530, bug #59695 reappears. It doesn't happen in normal circumstances, eg after reboot. More importantly, issuing hdparm -B 254 /dev/sda has no effect - the disk still keeps regularly parking.
The problem is that some process issues the command 'hdparm -S 12 /dev/sda' when I resume without power attached and this overrides the hdparm -B 254 command (see notes in comments below). A hdparm -S command to reverse the effects of hdparm -S 12 is not issued when power is reattached.
I used smartctl in a script to show frequency of disk parking after resume (date and time is included), issued a hdparm command which appears to work, but the script shows that disk parking continues afterwards:
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 11236
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 11279
setting Advanced Power Management level to 0xfe (254)
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 11285
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 11287
If I do the same thing after a reboot on power, the load cycle count does not change, which is what I expect.
This problem didn't happen in Intrepid, and I believe it has only recently started happening in Jaunty (since the beta was released).
DistroRelease: Ubuntu 9.04
Package: pm-utils 184.108.40.206-0ubuntu4
Uname: Linux 2.6.28-11-generic x86_64