I didn't hear back from anyone on this and am replying to give it a second chance.... If this is not the right mailing list for questions like this please let me know and I will move the discussion elsewhere.
Thanks,
Tim
On Sep 8, 2011, at 8:35 PM, Tim Nufire wrote:
> Hello,
>
> A quick update on this... With the help of Mark Lord from the hdparm team I found the following code in libata-core.c which should do what I need:
>
> if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
> tried_spinup = 1;
> /*
> * Drive powered-up in standby mode, and requires a specific
> * SET_FEATURES spin-up subcommand before it will accept
> * anything other than the original IDENTIFY command.
> */
> err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
> if (err_mask && id[2] != 0x738c) {
> rc = -EIO;
> reason = "SPINUP failed";
> goto err_out;
> }
> /*
> * If the drive initially returned incomplete IDENTIFY info,
> * we now must reissue the IDENTIFY command.
> */
> if (id[2] == 0x37c8)
> goto retry;
> }
>
> I've verified that this is in 2.6.32 but it isn't working on my system which uses Silicon Image port multipliers to connect 45 drives. On a hunch, I downgraded to Debian 4 with 2.6.26 and everything working as expected... This means that either something broke between 2.6.26 and 2.6.32 *or* the Debian team is compiling the kernel without support for this.
>
> Does anyone have a guess as to what's going on here?
>
> Thanks!
>
> Tim
>
>
> On Sep 1, 2011, at 2:34 PM, Tim Nufire wrote:
>
>> Hello,
>>
>> I'm using 3TB Hitachi Deskstar 5K3000 drives in a custom 45 drive high density enclosure (http://blog.backblaze.com/2011/07/20/petabytes-on-a-budget-v2-0revealing-more-secrets) and need to limit the inrush current at startup by stagger the drive spin-up. Since I can't control drive power through by backplanes, the best way to do this appears to be by enabling the Power-Up In Standby feature on the drives via 'hdparm -s1'. Unfortunately this is not working for me....
>>
>> I believe the problem I'm having is that the Hitachi Deskstar 5K3000 drives require a SET FEATURES subcommand to spin-up to active state when the device has powered-up into Standby. I'm getting this from section 9.1 in the following spec:
>>
>> http://www.hitachigst.com/tech/techlib.nsf/techdocs/FFDF1FA949853DBD8825785A005CBC55/$file/DS5K3000_US5K3000_OEMSpecRev1.1.pdf
>>
>> Section 4.17 in the ATA spec that I found at http://t13.org/Documents/UploadedDocuments/docs2006/D1699r3f-ATA8-ACS.pdf says the following:
>>
>> A device may implement a SET FEATURES subcommand that notifies the device to spin-up to the Active state when the
>> device has powered-up into Standby. If the device implements this SET FEATURES subcommand and power-up into Standby
>> is enabled, the device shall remain in Standby until the SET FEATURES subcommand is received. If the device implements
>> this SET FEATURES subcommand, the fact that the feature is implemented is reported in the IDENTIFY DEVICE or IDENTIFY
>> PACKET DEVICE data.
>> .
>> .
>> .
>> If the device does not implement the SET FEATURES subcommand to spin-up the device after power-up and power-up into
>> Standby is enabled, the device shall spin-up upon receipt of the first command that requires the device to access the
>> media.
>>
>> Section 7.47.8 then says:
>>
>> Subcommand code 07h shall cause a device that has powered-up into Standby to go to the Active state (see 4.17 and figure 7).
>>
>> From this I'm concluding the following:
>>
>> 1) Not all drives require the spin up subcommand which explains why this works for some drives
>>
>> 2) Our Hitachi drives require this command and the libATA drivers don't appear to support it
>>
>> Is this right? If so, is there a reason why the libATA does not support this feature? I'm running Debian 5 with a 2.6.32 kernel... Has this been implemented upstream? Would this be a feature hard to add/backport?
>>
>> Thanks,
>> Tim--
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