torrents & hash failures? how many is too many?

I downloaded an episode of grey's anatomy that I missed last season.
It was about 350 megs, I had 19 hash failures during the download and
each block was one meg. This is common for me to have this many, is
this normal for other people out there?

I always have to double check the torrents also and do a "recheck" when
the torrent has finsihed as often it picks up corrupted parts then also
which it seemed to have missed doing the first check.

So what I'm wondering is
1) is this normal or do I have a problem somewhere?
2) ideas on what to look for next? and how to check things?

Thanks

 

If this is the case there must be something wrong with your torrent
client, your RAM, your harddrive or some other part of your system,
there's no way you should have to do a recheck. Try µTorrent, or Azureus.

 

Tried both of them, same with both. So it isn't the client.
I dont think its the ram because surely memtest would have picked a
problem up in 12 hours of thrashing the memory when on a torrent i get a
hash failure every 10 minutes almost.

I'll try a new network card that is probably the next logical thing to try.

Wonder if it could be the CPU?

 

Yes forgot to add that i ran memtest for 12 hours and no problems were
found. On torrets I get a hash failure every 10-15 minutes generally.

 

What sort of connection are you using? ADSL? Interleaving off?
If you host & seed a torrent from a machine on your network (Azureus can
do this), do the errors occur?

 

Yes interleaving is off on my ADSL connection plus I have a pretty
horrid connection, my line quality is quite bad.

Haven't tried that. I will try that now and see what happens. Thanks
for the suggestion.

 

Ok well I hosted some massive files and did downloaded accross the LAN.
No errors at all.

I tried downloading on another PC from the internet and got errors so
its probably not the computers

I am using smoothwall so I'm thinking its down to

1) terrible internet connection (which i have) but could this give
errors or does tcp error correction rule this out?
2) faulty network card on the internet interface in the smoothwall box
3) faulty adsl modem
4) faulty ethernet cable? going from adsl modem to smoothwall box.

What do you think is most likely out of that lot?

 

The internet connection, since you say the line's bad and interleaving's
off (not a good combination). Get your ISP to turn interleaving on, see
if that helps.

 

Check your hard disk SMART mode? for a log of your hd health.

Also you say every 10 to 15 minutes? is a virus scanner kicking in?

 

Right then, as I understand things the bittorrent is all about getting a
whole heap of slices delivered to your PC in fine condition. It has in
built checks and tests each slice and if it fails then, Could we have
another copy please.

What screams out to me in this thread that, all is well on the first check
but things fail on the second check.

Can the Zipper, get another PC on his torrent connection for a GB or two
blast and see what happens.

We have an intermittant fault here yes?

 

No. I might have one error every several downloads.

max / max DSL in the Manawatu

 

More likely to be something on / in the network.

The hash checking is to ensure the data downloaded is free of errors - and
it isn't.

That won't be your CPU.

 

In my experience hash failures can be caused either from:

1/ dodgy router/switch/NIC

2/ dodgy sender.

You shouldn't have to do multiple checks, as the hash check should be
accurate. Which BT client are you using?

Solutions:

1/ power-cycle router/switch/NIC

2/ ban dodgy sender from sending anything to you.

IMHO the second is the much more likely.

I'm currently in the process of downloading (over dialup) the last 220megs
of a 3.5gig ISO DVD image (Open SuSE10.1r2), and I've only had 11 hash
failures.


Aquilegia Alyssum

 

Could it be somebody trying to run interference to prevent you downloading
that material?

 

means nothing, did you do a loop of the tests.

I agree it is not relevant to your problem, but memtest should be run for
one loop at least.

 

Thanks to everyone that replied.
After many tests and trying different PC's and different adsl modems, I
determined that it was the connection.

I requested interleaving to be turned on and have since downloaded the
same torrent with 0 hash failures.

So I guess if you have a horrid connection interleaving is quite important.

I called Telecom to get them to test my line as the exchange is only
2.5km's from my house and yet my attenuation is at 62 which according to
BT's guidelines should only be supplied with a 1 megabit adsl package.

Telecom ran their tests and said can't find any faults not that I
expected they would, they don't consider crappy ageing copper a fault.

Hopefully when I move in the new year to my new house which is 500
metres from a different exchange I will see much better quality, fingers
crossed.