Re: USB drive spins up every hour

[Camaleón <noelamac@gmail.com>]

On Fri, 23 Mar 2012 22:15:38 -0400, Stefan Monnier wrote:

>>>>> My USB-connected drive spins up every hour (or even half-hour).
>> (...)
>>>>> Any idea what it might be and how to find out and fix it?
>>>> IIRC, this setting can be defined using hdparm ("-M" flag and also
>>>> "/usr/ share/doc/hdparm/README.acoustic") but as the man page/doc
>>>> says, the possible options for this value depend on the hard disks
>>>> model.
>>> hdparm only sets the timeout for spin DOWN.  My drives spins down just
>>> fine, the problem is that it spins *UP* even though I don't use it.
>> I think both settings can be tweaked. "man hdparm" is long but worth
>> for a slow reading.
> 
> You're confused.  Spin up happens when the drive is accessed and that's
> all there is to it.  

Well, that's not always the case. There are external drives which have 
embeded in their firmware the power saving routines and spin-down/up 
automatically based on that, regardless the disk is being accessed or not.

> There is no setting for it because there's no reason to spin up the
> drive if there's no access to it, and there's no way to satisfy an
> access without spinning the drive, so there's basically no choice of
> when to spin up, from the drive's point of view (except for accesses to
> meta-data via things like smartctl and hdparm).
> 
> My problem is that apparently some application somehow accesses the
> drive but not in a way that block_dump catches.

Mmm... if you so sure the disk is awaked by an external application, then 
don't mount it unless you need it, that way the disk can be still powered 
on but it will inaccessible for the system and programs.

>          Stefan "already familiar with the hdparm man page, which
>                 incidentally also mentions that these operations often
>                 don't work for USB-connected drives ;-)"

This is hit-or-miss, you have to try first :-)

Greetings,

-- 
Camaleón