[gentoo-amd64] Re: Transmission, bittorrent client pausing downloads

[Duncan]

Tom <uebershark@××××××××××.com> posted
20090415143440.6553d0dd@ViciousVincent, excerpted below, on  Wed, 15 Apr
2009 14:34:40 +0200:

> Hi, I've been using transmission as my main bittorrent client for ages
> now.
>
> For some odd reason, it randomly just pauses all downloads. It normally
> would do this, when running out of disk space, which is not the case
> here..
>
> Any ideas?

This one's kind of random, but who knows?

This is based on LWN's "Notes from the LSF storage track" article as 
found at the link below.  More specifically, it's based on the first 
paragraph under ATA issues, about the problem with zero-length barriers.  
Apparently this causes some drives to power off briefly, possibly due to 
power-saving then powering up for the flush, drawing more power than 
expected.

http://lwn.net/Articles/328347/

It's causing problems with occasional lost data due to losing the cache 
in the power blink.  Naturally, this confuses the drivers and possibly 
the apps using the drive as well, particularly if an error is propagated 
up the driver stack to them during the momentary outage.

I wouldn't consider this very likely except that I just read it 
yesterday, so it was top of my mind when I read your problem.  It's 
possible, particularly if the problem is relatively recent, with newer 
kernels.  I'm not sure when those barriers were enabled and there's not a 
lot more info in the article than I posted, but the article does imply 
it's a fairly recently encountered problem.

More generally, it could be any similar issue that causes a temporary 
error.  There's a few temporary errors that could, if taken wrong by some 
layer of the stack (not necessarily transmission itself), cause the app 
to pause, thinking the storage is full, has been removed, or some other 
such thing.

BTW, I don't use transmission (I don't do much torrenting and I'm 
normally a KDE guy so what I've done has been with ktorrent), but if you 
take a look at my headers, you'll see I'm using pan.  Pan's lead dev is 
Charles Kerr, tho he hasn't done a lot with it for nearing two years 
now.  However, during at least part of that time I've heard he's been 
working on transmission. =:^)  It had apparently been abandoned or nearly 
so for some time, until Charles came along to work on it (that's only 
what I read, I don't know, no offense to anyone intended if it's a group 
effort).  Meanwhile, I've been quite active for years as a regular on the 
pan mailing lists (newsgroups as served thru gmane, just like this list/
group, where I read and reply with pan) and believe I may now be the 
senior regular there.  Thus, even tho I don't use transmission, I feel 
like I have a bit of a connection with anyone that does, since the 
project I've been a long time list regular for has as the primary dev one 
of the guys who has put a lot of work into transmission now as well. =:^)

So anyway, see if it has a mailing list.  If it does and it's as active 
as the pan user list, you'll likely find help.

Meanwhile, one other possibility.  If you run GNOME, see if you have the 
Assistive Technologies daemon (should be a process named at-spi-registryd)
running.  With pan it has been a problem, most often seen on Ubuntu since 
they apparently have it running by default now, but it could be a problem 
on other distributions if it's running, too.  Apparently, it polls the 
input and other devices very frequently, to the point it slows down a 
bunch of other stuff including pan downloading.  We tried and tried to 
figure that one out, finding out it was Ubuntu only (for the most part), 
then Ubuntu, only when running GNOME, which was strange as pan is a gtk/
gnome family app, then we were stuck for awhile and could only tell 
people to try KDE or XFCE when running pan.  But someone figured it out 
recently, apparently as he'd had problems with it sucking performance out 
of other things as well.

So anyway, if you have an at-spi-registryd process running, consider 
killing it unless you really need it due to being "alternately enabled".  
See if that helps.  On Ubuntu-8.10/Gnome at least, it's under System > 
Preferences > Assistive Technologies.  The instructions as posted on the 
pan list/group say uncheck "Enable Assistive Technologies".  The poster 
said he rebooted soon after and the problem was gone, but he didn't know 
if a reboot was required.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman