Hi,
> Is there anyway to get a hd out of sleep mode after putting it into
> that without a warm reboot?
>
> We have an embedded system that runs in cold tempertures, when the hard
> disk gets too cold, we put the hd into sleep and run out of CF, but
> when the temperture warms up, we want to get the hd back to usage
> without a reboot. Possible?
Is there any reason you can't use Standby mode instead of Sleep mode?
The disk still spins down, and you wouldn't have the trouble
of having to issue a reset to get it back online.


However, I've just re-read the hdparm man page, and it seems to be
different to last time I used standby/sleep mode:

-Y Force an IDE drive to immediately enter the lowest power consumption
sleep mode, causing it to shut down completely. A hard or soft reset is
required before the drive can be accessed again (the Linux IDE driver will
automatically handle issuing a reset if/when needed). The current power mode
status can be checked using the -C flag.

The part in brackets seems to imply the kernel can issue the reset and get the drive
back online.
Perhaps this is a new feature you should investigate..

Regards,


--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
Damion de Soto - Software Engineer email: damion@cyberguard.com.au
CyberGuard Corporation ---- ph: +61 7 3435 2809
| Custom Embedded Solutions fax: +61 7 3891 3630
| and Security Appliances web: http://www.cyberguard.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
---- Free Embedded Linux Distro at http://www.snapgear.org ----

J Jackson wrote:
> errr..... depending on your setup there are issues.
> If ANY of the software/configuration data of your system is on the
> harddrive, then after you put it in spindown mode, it needs to read the
> disk and spins it back up!
OK, that makes sense. I'll try going into init 1 and run my stuff out
of CF.

>
> Maybe all your OS stuff is on the CF. If so I can't see what the problem
> is.
I'm running out of ramdisk, booting out of CF
>
> I've used spindown and putting the drive in standby etc, with hdparm, and
> the next time you accessed the drive the kernel does the necessary to
> bring it to life automagically.
>
> see some comments in
>
> http://www.comp.leeds.ac.uk/jj/linux/sbc.html#Configuring%20Spindown
>
>
Thanks