laptop-mode-tools uses hparm -B 255 instead of 254
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
laptop-mode-tools (Debian) |
Fix Released
|
Unknown
|
|||
laptop-mode-tools (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
Binary package hint: laptop-mode-tools
regarding /etc/laptop-
Using hdparm -B 255 is unpredictable because it's undefined in the ata/sata specs. This is relevant to people who are using CONTROL_
Please sync laptop-mode-tools from Debian to fix this issue. Quoting Bart Samwel, Debian maintainer of laptop-mode-tools, from
https:/
[quote=Bart Samwel]
......
......
The only thing that
should change in that area is that the default HD powermgmt settings in
the laptop-mode.conf should be changed to 254 instead of 255, but
that'll happen automatically the next time they sync up with Debian.
......
......
[/quote]
tferero received an email from Bruce Allen. From :
http://
[quote=Bruce Allen]
Hi T-,
I just learned about this buzz from a colleague yesterday.
I don't have any experience with your Samsung drive. I suggest that you
run a sort self-test '-t short' and wait until it completes. The drive
age should then be shown in the self test log. Then experiment with the
different -v and -F options to see how the drive is storing its lifetime.
IMPORTANT INFORMATION BELOW: PLEASE PASS BACK TO THE UBUNTU COMMUNITY
I think that the -B value of 255 is incorrect. You should use 254 for
maximum performance. 255 IS DOCUMENTED AS 'RESERVED' IN THE ATA/SATA
SPECS. THE BEHAVIOR OF -B 255 THUS IS NOT PREDICTABLE AND IT MAY HAVE NO
EFFECT. Also according to the ATA/SATA specs any value greater than or
equal to 128 will 'not permit the device to spin down to save power'. So
128 will reduce power use as much as possible but not permit spin-down.
References:
http://
PDF page 273 Document page 253
Table 43 (and the paragraph immediately following it).
So I suggest you try some different -B values such as -B 254 or -B 128.
The hdparm man page says 'values of 255 will disable Advanced Power
Management'. I think this is a mistake in the man page. According to the
ATA/SATA specs referenced above, the value 255 is reserved and has vendor
dependent meaning (or has no effect).
Cheers,
Bruce
[/quote]
Bruce Allen is :
* author of "Monitoring Hard Disks with SMART", Linux Journal, 2004) :
http://
* maintainer of the website http://
blackhole54 notified us here about this here :
http://
The bug about hdparm's misleading feedback about -B values :
https:/
Related branches
description: | updated |
description: | updated |
Changed in laptop-mode-tools: | |
status: | Unknown → Fix Released |
A merge request has already been filed in bug #164387.