I would say the manpage of hdparm is wrong. On one of my laptops 255 doesn't work (stays at 128) an on the other issuing 'hdparm -B 255 /dev/sda' results in setting the value to 254. But I am not sure that it is the right way to set it to anything other than the default 128 - the temperature of the harddrives on both laptops increased around 5-6 °C (up to 47 °C on one laptop) after switching the head-parking of. And that only with not much load on the harddisc - with heavy disc activity the temperature should even go higher. And I think it is wrong that Windows overwrites the default BIOS/harddrvive firmware settings - I checked it on 4 laptops (2 WinXP and 2 W2K) with the Win-port of hdparm and smartctl. Under Windows the power management is also set to 128 - and I can hear the same click when the head moves to its parking position. On the two Win2K laptop's (which never have seen anything else than Windows) the average load-cycle is 16.4 times/hour (calculated from Load_Cycle_count divided by Power_On_hours from smartctl). On my main laptop (running Debian etch) I took the values over a 4 hour period (laptop was idle during this time) and during this time I got an average of 120 load_cycles/hour - would explain my high Load_cycle_count of 390000 on this machine.
So to me it seems that Linux isn't doing anything else than windows (better said - both are doing nothing - it's the BIOS/hdd firmware) - put the heads after the same amount of time into parking-position - so it's not the fault of the not changed power-management value under Linux - and I think it should not be changed because of the otherwise increasing drive-temperature (which could also lead to an earlier dead of the harddrive). The difference why Windows has a so much lower load-cycling per hour seems to me that in windows the heads stay in parking position when the laptop is idle ( another test over 4 hours under WinXP gave 3 load-cycles/hour when idling) for a much longer time than under Linux. In Linux the heads are unparked right after parking - and THAT'S the big problem - we should find out what process/daemon is accessing the harddisc so often that the heads can't stay in parking position, and then fix that behavior. BTW: on a (I think RedHat or Fedora) mailinglist I read that "the annoying harddisc clicks" didn't occur with kernel 2.6.9 and older. If it is the kernel itself who accesses the disc so often, and this was not he case for kernel 2.6.9 and older, that would explain why this problem didn't catch someones eyes earlier - I think people are running Linux on laptops for longer than the last two years. -- Hard drive spindown should be configurable https://bugs.launchpad.net/bugs/17216 You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
