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Bitcoin => Bitcoin Technical Support => Topic started by: jock45 on August 25, 2012, 12:28:24 PM



Title: Bitcoin QT not downloading blocks
Post by: jock45 on August 25, 2012, 12:28:24 PM
Hello Everybody,

I was hoping someone could help me here.

I've just started using bitcoin qt 0.6.3. It downloaded the full block chain and I made a few small transactions.

Now, though, the client won't download any more blocks. I'm stuck on block 194998 last received 3 days ago.

It says:
"WARNING: Displayed transactions may not be correct! You may need to upgrade or other nodes may need to upgrade."

I have sufficient disc space.
I deleted the bitcoin directory without deleting anything in appdata, this had no effect.

Anyone any suggestions of what I could try?

cheers.


Title: Re: Bitcoin QT not downloading blocks
Post by: BitcoinObmen on August 28, 2012, 02:47:19 PM
First of all, backup your wallet.dat (& maybe addr.dat).
Run bitcoind -rescan. If don't helps, delete everything in AppData\Roaming\Bitcoin
except wallet.dat, then run bitcoin client again.
It will re-download the whole blockchain.


Title: Re: Bitcoin QT not downloading blocks
Post by: Potato on August 28, 2012, 10:10:11 PM
Or just use an online wallet like https://blockchain.info/wallet/


Title: Re: Bitcoin QT not downloading blocks
Post by: deepceleron on August 28, 2012, 10:36:49 PM
If you have sufficient connections to other nodes, then database corruption is likely. In the %appdata%\Bitcoin data folder, check the end of db.log and debug.log, which will have normal logging until near the end and then the error should be apparent.

The -rescan option only looks for missing payments to you, it does nothing to discover blockchain errors.

The command line option that may actual detect (repair?) errors is checkblocks. The options below give the most extensive check possible, which will take a long time, but slightly less than redownloading the blockchain:

>bitcoin-qt.exe -checkblocks=0 -checklevel=6




Title: Re: Bitcoin QT not downloading blocks
Post by: brewsterkahle on September 08, 2012, 04:07:50 PM
I am having the same problem, with the same message, but at block 194995.

was there a hack at that point in the block chain?

did starting again help?   it took me a day to get to that point, so I am a bit loathed to start again.

Thank you.


Title: Re: Bitcoin QT not downloading blocks
Post by: old_engineer on September 09, 2012, 11:15:25 PM
I am having the same problem, with the same message, but at block 194995.

was there a hack at that point in the block chain?

did starting again help?   it took me a day to get to that point, so I am a bit loathed to start again.

Thank you.

It's probably just a database corruption issue, with resolutions as noted above.  There have been no hacks in the blockchain that I know of, besides one years ago when someone created ~2 billion bitcoins (integer overflow exploit), but that block is no longer in the blockchain. 

Downloading the blockchain taxes the CPU, network, and disk storage subsystems all at once, and I think this is why many systems have issues with the task.  One time, my OSX Lion macbook pro had a hard crash with a mutex spinlock problem when downloading the blockchain.  After restart, I found that my blockchain was corrupted, and I had to delete the database files (all but the wallet file in ~/.bitcoin in linux or ~/Library/Application Support/Bitcoin on osx) and restart from scratch, and it worked just fine on the second try.


Title: Re: Bitcoin QT not downloading blocks
Post by: brewsterkahle on September 10, 2012, 02:30:31 PM

You were right, just rerunning worked on my Mac Air.   Thank you.

-brewster

I am having the same problem, with the same message, but at block 194995.

was there a hack at that point in the block chain?

did starting again help?   it took me a day to get to that point, so I am a bit loathed to start again.

Thank you.

It's probably just a database corruption issue, with resolutions as noted above.  There have been no hacks in the blockchain that I know of, besides one years ago when someone created ~2 billion bitcoins (integer overflow exploit), but that block is no longer in the blockchain. 

Downloading the blockchain taxes the CPU, network, and disk storage subsystems all at once, and I think this is why many systems have issues with the task.  One time, my OSX Lion macbook pro had a hard crash with a mutex spinlock problem when downloading the blockchain.  After restart, I found that my blockchain was corrupted, and I had to delete the database files (all but the wallet file in ~/.bitcoin in linux or ~/Library/Application Support/Bitcoin on osx) and restart from scratch, and it worked just fine on the second try.



Title: Re: Bitcoin QT not downloading blocks
Post by: Velkro on September 02, 2017, 03:03:36 AM
Or just use an online wallet like https://blockchain.info/wallet/
I would never recommend an online wallet.
Dont do that.

Reasons can be vast. I mean, it could be fualty HDD, faulty RAM, poor internet connection, low HDD space.
You name it, try to reinstall, always backup your wallet first, then try diffirent things. Try on another computer etc.


Title: Re: Bitcoin QT not downloading blocks
Post by: odolvlobo on September 02, 2017, 09:54:11 PM
Or just use an online wallet like https://blockchain.info/wallet/
I would never recommend an online wallet.
Dont do that.

Reasons can be vast. I mean, it could be fualty HDD, faulty RAM, poor internet connection, low HDD space.
You name it, try to reinstall, always backup your wallet first, then try diffirent things. Try on another computer etc.

You are replying to a 5 year old post.