Hi, Maxim Kammerer wrote (02 Mar 2013 20:39:35 GMT) : > On Sat, Mar 2, 2013 at 9:49 PM, intrigeri <intrig...@boum.org> wrote: >> If these settings were seriously >> wrong, I guess we would have seen quite a lot of bug reports in Debian >> during the Wheezy development cycle.
> Like these? Just a few examples. > http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=684241 > https://bugs.launchpad.net/ubuntu/+source/hdparm/+bug/913050 Maxim: thanks for the pointers. I'm now convinced (and have started doing what's needed to fix this in Wheezy, by the way). Tails developers: I've rewritten the branch history to use 128 instead of 127, and improved the commit message to explain why. >>> Having 254 for everyone on AC is unreasonable, in my opinion. >> >> I concur with Alan: would you please share some insight about why this >> is unreasonable? > I don't think hard drives will ever spin down with -B254, even with -S > (again, it has been some time, so I might be wrong — I think the > laptop on which I saw problems with -B127 never spun down with -B254, > so this might not be universally true/untrue). Given that the people > recommending use of -B254 don't really understand the issue (e.g., > -B128 would fix the issues with a drive constantly going idle from due > to -B127 just the same, and sometimes the problems result from using > -B255 with older hdparm versions that didn't treat the parameter > correctly), I would say that -B128 is the correct value to use, when > -S is also specified (which laptop-mode does for IDLE_TIMEOUT > parameters). Thanks for the explanation. There's https://ata.wiki.kernel.org/index.php/Known_issues#Drives_which_perform_frequent_head_unloads_under_Linux, but after a quick look at a few reports, they're indeed either old or not totally convincing (i.e. there's no indication that -B 128 was not enough), so at this point I could be convinced -B 128 is the way to go. However: the original bug we had reported against Tails 0.16 a few weeks ago made it clear that the default -B 128 triggered the problem them, while -B 254 fixed it. Even if we assume that most cases were reported and analyzed by people who "don't really understand the issue", and would simply be solved by -B 128, there's apparently at least one case in the wild where -B 254 is needed. I believe that one diagnosed, debugged and reported case against Tails means many more potential real world cases. So, I'm still in favour of using -B 254 for Tails. But well, I guess Maxim will come out with a few bug reports that clearly show that -B 254 is harmful ;) If this does not happen within a few days, my merge request holds. Cheers, -- intrigeri | GnuPG key @ https://gaffer.ptitcanardnoir.org/intrigeri/intrigeri.asc | OTR fingerprint @ https://gaffer.ptitcanardnoir.org/intrigeri/otr.asc _______________________________________________ tails-dev mailing list tails-dev@boum.org https://mailman.boum.org/listinfo/tails-dev
