Messages in this thread | | | From | "Janos Haar" <> | Subject | Re: HDD power up in standby | Date | Tue, 15 Dec 2009 02:21:58 +0100 |
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Hello,
----- Original Message ----- From: "Robert Hancock" <hancockrwd@gmail.com> To: "Janos Haar" <djani22@netcenter.hu> Cc: <linux-kernel@vger.kernel.org> Sent: Tuesday, December 15, 2009 2:02 AM Subject: Re: HDD power up in standby
> On 12/14/2009 04:22 AM, Janos Haar wrote: >> Hello list, >> >> I have posted to the common, because this theme is for more lists (ide, >> sata, scsi), i think.... >> >> I know you will not like me guys, but i have one wish.... :-) >> >> I am building cheap but big storages, and after 12 drive / PC i have >> faced >> with one problem: >> The too much spinup current wich made by the 12-16 drive at the same >> time. >> In my actual case, in 12V, there is more than 2A / drive for some >> seconds. >> >> I know, in SCSI, there is a jumper for this, and the card can wake up the >> drives one by one, but i am using 2TB drives, and in SCSI/SAS this have >> horrible price... >> I have done some invesrtigation, and found this: >> The most of the simple sata drives handles the PUIS mode (by set >> features ata command), but unfortunately >> only the professional and expensive raid cards supports the wakeing up. >> If the cheap cards founds only 0 byte drives, this is not a problem at >> all, >> because linux usually not use BIOS support fortunately. :-) >> But i have found when i have spent a little time in google, and in the >> documentation, linux doesn't support PUIS. >> >> I think this would be great, and (relatively) simple to implement this >> feature. >> I can imagine in this way: >> Wake up from PUIS is disabled by default, but can be enabled by command >> line >> parameter, or compile time configuration. >> The drivers should send the wake up command one by one to the drives, >> waits >> for RDY DSC, and than scan the drives, and register.... >> >> What do you think? > > As far as I can see, if the drive reports it's in power-up in standby mode > from the identify response, the kernel will send the command to spin up > the drive. It might depend on whether parallel scan is enabled for the > controller as far as whether they actually spin up one at a time, however.
I am working with 2TB Hitachi drive wich is set to PUIS, and reports itself as 0 byte, but existing device (pcb factory alias), but with my promise card, the kernel see only bad geometry and disable the port only. :-( I have missed something?
> >> >> (Now i am searching for the solution to send the wakeup command by user >> program, and than do a "hotplug" in software only, but this is not an >> "elegant" solution...) >> >> >> Best Regards, >> Janos Haar >>
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