Laptop: Hard drive wakes up every 5-10 seconds

[Bill Davidsen]

Kevin Kofler wrote:
> Michael Cronenworth wrote:
>> Why would Linux be waking up every 5 to 10 seconds to write to the disk
>> when I am sitting at my desktop or sitting at the login screen? (i.e. No
>> programs running. Only 40 total wakeups seen in powertop)
>>
>> - Seagate 320gig SATA
>> - XFS filesystem, relatime mount option enabled
>> - link_power_management_policy set to min_power
>> - vm.dirty_writeback_centisecs is set to 1500
>>
>> I even unmounted /boot (default ext3) but that did not change anything.
>> Every 5 to 10 seconds I see the HDD light flash and sometimes I hear a
>> very faint "beeping" like the drive is waking up or powering off,
>> whichever it is doing.
> 
> Try tweaking your hdparm settings.
> 
> Adding this to your rc.local might help:
> /sbin/hdparm -S 255 /dev/sda
> /sbin/hdparm -B 255 /dev/sda
> 
I think the O.P. was trying not to spin up the drive so often, not keep it 
running to pull the battery down... setting the filesystem flush and 
/proc/sys/vm/dirty* values to be reluctant to write will halp here, and allow 
powersave (-B) with a low value is more likely to be what is wanted.

NOTE: setting the flush time to a high value leaves data in memory and not on 
the drive, use of a manual "sync" command is desirable if you modify critical data!

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot