failed in hash check

[rpwicked]

Hello everyone once again. I checked through the forum and couldn't find anything regarding my question. I am using version 1.27 on an XP pc. I followed your set-up guide to the tee, I know it's set up right. I get good speeds with just about everything I dl.

This particular torrent is taking a while, it's large at 6.43 gig, so I expect it to, and I am getting decent speeds, that's not my problem. My question is, when I check under the logs tab, I see allot of, downloaded piece #**** failed in hash check, 2048 kb dropped. I've seen this in other torrents just not this many. Mostly I see how many peers the tracker brought back with this occasional warning. But this torrent the log is full of this. What exactly does this mean? Am I going to start to watch this and then have pieces missing, or is this just telling me that a certain piece was bad and bc will find a peer with the same piece in good condition? I think and hope it's the latter.

You guys have helped me out greatly in the past and I'm sure someone can explain this to me, or let me know if my guess is remotely close. Like I said, it's not affected my dl speed, or it doesn't seem to be. I'm just more or less curious about what it means.

Thanx in advance

rpwicked

[The UnUsual Suspect]

You are correct, it means that you downloaded a piece of data from a peer and it wasn't 100% intact, so the bittorrent protocol will delete that piece. This assures you that nothing nasty like a virus could infect a piece of data and survive.

The cause of this could be data damaged in transit, data damaged after it was received by you due to harddrive and/or file system errors, or a hostile peer sending bad data to interfere with p2p downloads.

I can't tell you which of these most common reasons is effecting your torrent, but if you get this on all torrents, then I'd suspect the problem is on your system and I'd run some scans. If it only happens on one (or few) torrents, then it could be a bad peer, either intentionally or due to poor connection.

Also understand that the larger the torrent, the greater the odds of finding errors.

There are also some conditions that usually only effect old routers where they will rewrite packets of data to change what they believe is an external IP address to match your internal IP address, but in this case, the same piece will fail has on every attempt, no matter what peer it comes from. This will randomly effect torrents greater then about 4gB at least once (one piece that will never download intact). It's not likely you have this problem though, and I wouldn't suspect it unless your download stops at 99.9% AND you continue to download the same corrupt piece from many peers.

[rpwicked]

Thanks for the quick reply. I was hoping I was right. Good to know. I scan my system regularly, and thankfully I don't get this with every torrent. I was just a little overwhelmed when I clicked the log tab and the whole section down there was yellow. I also noticed that a few of the logs were the same number piece, then it went back to telling me about the tracker. I'm assuming that it found a good version of those certain pieces when I stopped seeing the warning. I'm glad to hear what you told me. I would've been upset if this download was messed up in some way.

Thanks again, very informative. I love learning stuff

Edited July 25, 2011 by rpwicked (see edit history)

[The UnUsual Suspect]

as long as your download completes, then there probably is nothing to worry about. If that specific piece never finishes, then you may have a router problem, but that doesn't seem likely if the errors stopped.

However, if this is your first torrent that's larger then 4gb, then you wouldn't be likely to see that problem before.

For anyone who suspects their router is damaging pieces like this, the easiest way to confirm is to bypass your router by connecting direct to your modem and see if the piece completes. If you do confirm it's the router, then try disabling "gaming mode", or updating the devices firmware. If this doesn't help, then it's probably about time to get a better router.

[rpwicked]

I have been thinking that it's about time for a new router, as mine is pretty old. I'll probably just go ahead and get a new one. Thanks again for all your help, this time and in the past, and your super fast response. I'm not used to fast answers. Before I started using Bit Comet, I had a different client, I won't mention names- but it does rhyme with poo current- sort of.lol, anyways, their forum was horrible. It would normally take weeks to answer a post.

Your fast and always helpful answers are appreciated. Thanks

rpwicked

[The UnUsual Suspect]

haha, thanks for the complement.

Of course I agree. I think we have a great support system here, even better then many commercial products I've seen.

If only all members could read the rules and provide the info we need to help them...

[cassie]

rpwicked, you've just made my day :)

You have no idea how refreshing it is to have someone actually thank you and commend you for your help, when a great number of users only bother to post in order to complain... sometimes, it just makes your eagerness drop to the gutter... :(

Once again, thanks. :)

[rpwicked]

I just try to give credit to where or whom it is due. The whole staff here is excellent, everyone on it deserves a thanks. But I'm glad I made your day, Cassie. And to everyone who posts complaints, all I have to say to them is they should get another client and experience it's forum. Then they would come to appreciate this forum and all who keep it going. To the whole BC team, keep up the good work, it surely is appreciated.