Slow speed on transmission

[jrosado]

I use oleg firmware. I think the problem is on the high cpu usage that big torrent files make. At the moment, I'm downloading a 40GB torrent (about 180 files of 350MB and 700MB) and the cpu usage is very high (allways above 2.0). In this torrent, all the files have not been yet created!

Before this i tryed a single 700MB torrent file, and got speeds of 450KB/s

So, i will wait to see if the asus can manage this other torrent (is almost on it 24 hours, and not all of the 180 files have been created!)

[olfa]

Oh man, this whole transmission experience is lately pure masochistic. Previous build was finally pretty good for me. I was getting whole day constant 40 KB dl speed on public torrent with only 4 seeds and on private torrents my line was maxed 60 seconds after start. As I can't resist to newest builds always hoping for better (don't we all?) I tried today's build. It took me 45 seconds to upgrade and restart transmission. Guess what, I was getting much lower speeds on the same torrent (tried several restarts). Well, one can attribute this to the torrent nature (what is confirmed because while I am writing this post speed goes steadily up).

So I vote that previous build is very good and for the latest build time will tell. I think that transmission is back on track.

[oleo]

I think that transmission is back on track.

I am also sharing your opinion. Latest build 0.96+ (4366) maxes my line as never before.

For huge torrents I cannot tell. I suggest that you install procps package or atop and use top for displaying system load. You will see that normally CPU is 30% idle at system load over 1.0. This means that CPU is not the bottleneck. It is rather i/o.

It helps somehow if you increase cache by upgrading memory. But this is hardware mod. Oleg for example increased its wl500gP to 128MB. I've upgraded two mine wl500gx to 64MB with just 20€ investment.

[jrosado]

Here is my top result:



I do think that the problem is the cpu usage on i/o on the usb hard disk.

Of course if i put transmission with simple torrents, i get great speeds, only limited by the USB speed to the external hard disk.

I don't know if upgrading the memory is worth the risk.

One thing i know is that maybe if i used a NAS disk connected to one of the ethernet ports, the system use could be lower.

I did post a question on this forum about bulding such a system (here), but no one answer

[oleo]

It is better to go for NAS that has provision for Transmission than using external NAS for IO. I could not tell you if this approach could help you. Look for router with directly attached disk. Like FSG-3 or WL700gE. Visit www.nslu2-linux.org for more details.

I see from your top that your transmission uses 44MB of memory. 20MB resident. 12MB shared. So you are swapping all the way. There is nothing you could do to increase speed. Except somehow lowering memory usage. Maybe rtorrent is better on that although transmission always claimed its lightweight. atop could tell you if memory consumption has gradient and possible leaking.

Kill rcamd, waveserver and other unused modules to squeeze more memory.

[mancub]

Yes, this latest Transmission build has far better speeds than the previous ones so I think if nothing else surfaces we should stick with it.

[oleo]

I would also like to see that Transmission has a stable development, but recent code changes were extreme, from my point of view. I've backed at 0.82 for long time, tried 0.9x for several times and did not want to upgrade until it stabilizes. But meanwhile some users wanted newer releases. I've resisted for some time. Then bzhou upgraded Transmission and broke things. I've corrected things. Optware lost its ability of older versions and so on. So the saga continues. It looks like there will be Transmission 1.0 in near future. Anyway, I will not upgrade Transmission untill 5th Jan. 2008 as my 500GB disk failed to go through fsck and the whole computer is inaccessible to me until then
HNY

[mancub]

Hmm, there still might be something wrong with this latest Transmission.

I am at 50 peers (max) on two torrents, yet only downloading from 5-10. That's rather wasteful especially if there are over 200 peers on both torrents who could get me some data.

It appears that once a limit of 50 is reached things just grind to a halt or slow down considerably. When there are less than max peers (50) on a torrent, it seems healthy and things are progressing yet when max is reached we are back to the old story.

Just my impression from the last two torrents I tried that have been running for over 4 hours now...

[dzontra]

It looks like there will be Transmission 1.0 in near future.

Version 1.00 is just released.
----------
All Platforms:
+ Port forwarding now performed by MiniUPnP and libnatpmp
+ Ability to set global and per-torrent number of connections
+ Option to prefer not using encryption
+ PEX is now configured globally
+ Updated icon
-------------
HNY to all.

[mancub]

...and my hunch is that it's the encryption that's causing all of these problems with low number of peers connected and slow speeds so that turn-off feature in 1.0 will be welcomed.

[oleo]

With changeset 7522 I've added encryption support which is now turned off by default.
Use config file to change encryption to preferred or required.

PEX is ON by default and cannot be turned off, unless someone will request this feature.

[mancub]

oleo,

Thanks for keeping us up to date with the code. I have upgraded via ipkg to the latest available build (4523) and will report here on the progress.

[cvisco]

First, thanks everyone in this community, I learned so much here (and found out how much more there is to learn...)

Now, for the transmission, I am running version 1.0+r4523-1 and my findings are quite similar to this:

I am at 50 peers (max) on two torrents, yet only downloading from 5-10....
It appears that once a limit of 50 is reached things just grind to a halt or slow down considerably. ...

One more thing: when I do flashfs save, directories
/tmp/local/root/.transmission/cache/ and
/tmp/local/root/.transmission/torrents
are being included in /tmp/flash.tar.gz file. This would not be bad if there was no 64kB limit for committing it to flash because it is over 64kB - around 77kB).

Here is example:

[admin@wl500gp root]$ flashfs save
tar: Removing leading '/' from member names
tmp/local/
tmp/local/samba/
tmp/local/samba/private/
tmp/local/sbin/
tmp/local/sbin/post-boot
tmp/local/sbin/post-firewall
tmp/local/sbin/post-mount
tmp/local/sbin/pre-shutdown
tmp/local/etc/
tmp/local/etc/dropbear/
tmp/local/etc/dropbear/dropbear_dss_host_key
tmp/local/etc/dropbear/dropbear_rsa_host_key
tmp/local/root/
tmp/local/root/.mc/
tmp/local/root/.mc/history
tmp/local/root/.mc/ini
tmp/local/root/.mc/cedit/
tmp/local/root/.mc/Tree
tmp/local/root/.transmission/
tmp/local/root/.transmission/cache/
tmp/local/root/.transmission/cache/9fba70a5df2c24ee978eb720ae640e8de7cdd756-cli
tmp/local/root/.transmission/cache/da6f72a20cdfd7100926384a497615b85bff37dc-cli
tmp/local/root/.transmission/cache/74bd320ab694abc74e1860b883098dde54e2bda3-cli
tmp/local/root/.transmission/stats.benc
tmp/local/root/.transmission/torrents/
tmp/local/root/.transmission/torrents/9fba70a5df2c24ee978eb720ae640e8de7cdd756-cli
tmp/local/root/.transmission/torrents/da6f72a20cdfd7100926384a497615b85bff37dc-cli
tmp/local/root/.transmission/torrents/74bd320ab694abc74e1860b883098dde54e2bda3-cli
tmp/local/root/.rnd
-rw-r--r-- 1 admin root 77724 Jan  8 15:58 /tmp/flash.tar.gz
Check saved image and type "/sbin/flashfs commit" to commit changes
[admin@wl500gp root]$ ls /tmp/local/root/.transmission/cache
total 0
drwx------ 1 admin root     0 Jan  2 17:54 .
drwx------ 1 admin root     0 Jan  2 17:54 ..
-rw-r--r-- 1 admin root 33934 Jan  4 21:58 74bd320ab694abc74e1860b883098dde54e2bda3-cli
-rw-r--r-- 1 admin root  5768 Jan  7 10:04 9fba70a5df2c24ee978eb720ae640e8de7cdd756-cli
-rw-r--r-- 1 admin root  5754 Jan  6 17:49 da6f72a20cdfd7100926384a497615b85bff37dc-cli
[admin@wl500gp root]$ ls /tmp/local/root/.transmission/torrents/
total 0
drwxr-xr-x 1 admin root     0 Jan  4 21:58 .
drwx------ 1 admin root     0 Jan  2 17:54 ..
-rw-r--r-- 1 admin root 46242 Jan  4 21:58 74bd320ab694abc74e1860b883098dde54e2bda3-cli
-rw-r--r-- 1 admin root 14652 Jan  7 10:04 9fba70a5df2c24ee978eb720ae640e8de7cdd756-cli
-rw-r--r-- 1 admin root 14659 Jan  6 17:49 da6f72a20cdfd7100926384a497615b85bff37dc-cli

What would be the right path to take? Erase cache? Exclude these directories? Something else?

Thanks in advance.

[mancub]

cvisco,

I have put .transmission/ folder with the rest of my source/, work/ and target/ torrent folders, on the harddisk. Then symlinked to it from /tmp/local/root/ and saved the flashfs (and backed it up as well).

[mancub]

It appears that the speed limiter is broken in this last build.

I've set the max upload speed to 50 like I always do and I just saw a torrent being uploaded at 80. I didn't even know my connection could do that high...perhaps it was upgraded to 5Mbit/1Mbit but either way Transmission should not be uploading faster than 50KB/s. This worked fine before...