Re: Laptop mode causing writes to wrong sectors?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Vojtech Pavlik wrote:

The issue might be that these people are using

	hdparm -S xxx
	
	or

	hdparm -y / -Y

while a much better way to do

	hdparm -B 63

The -S option should in theory be safe, but I remember some drives did
behave unpredictably if this was used.

Well, some drives have a specific lower limit on the -S values that are supported. That's the only compatibility problem I've ever encountered with -S. (And you can find out if a drive has a lower limit by checking hdparm -i.)

-y/-Y is much tougher and some
drives will not work reliably unless first woken up manually before
issuing a read/write request.

In fact, -Y is problematic but -y usually isn't. -Y puts the drive to sleep and requires that Linux reset the complete IDE controller before using it again, while -y simply puts the drive in standby mode, leaving it up to the drive to decide when it spins up. I've never heard of any problems with -y.

On the other hand, -B is pretty safe on drives that support it, and all
IBM notebook drives do.

Not true, unfortunately. In fact, I had to change the default config of laptop-mode-tools a while ago so that it wouldn't use -B, as it seemed to be one of the *causes* of hangup/corruption problems. This was also an issue on Thinkpads, and I think it was also noted in the ubuntu bug I linked to earlier.

An additional problem is that the values for -B are not really standardized, while the values for -S are.

--Bart
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux