Bitcoin Core client extremely slow and unresponsive when synchronizing

[rubikus]

Bitcoin Client Software and Version Number: Bitcoin Core Version v0.14.1 (64-Bit)
Operating System: Windows 10 64 Bit
System Hardware Specs: 16GB/RAM, i7-2600K CPU with 3.40GHz, 1.5TB Western Digital WD15EADS-00p8b0
Description of Problem: See below
Any Related Addresses: -
Any Related Transaction IDs: -
Screenshot of the problem: -
Log Files from the Bitcoin Client: See below

Hello!

My Bitcoin Core client became extremely slow and unresponsive when synchronizing. It also hangs for seconds up to minutes when trying to click on something in the GUI. After synchronizing, it is usable. It was not like this in the beginning.

It took several hours to synchronize just the last 3 days. When synchronizing, it is almost impossible to use the client. When I just try to do a right-click (e.g. to copy transaction details) it takes about a minute until the context menu shows up. Also, the title bar shows "not responding".

The weird thing is that when I check the task manager, CPU load is low (<10%), network usage is low (<1MB/s, usually just a few KB/s), RAM usage is low (4GB/16GB), hard drive active time is almost 100% - but read/write is using only low bandwidth (less than 1MB/s). It did not behave like that some months ago. I upgraded to the latest version 0.14.1, but it does not make a difference.

My PC hardware is not that bad. I have 16GB/RAM, i7-2600K CPU with 3.40GHz, Win 10 64 Bit. Harddrive where the Blockchain is stored is a 1.5TB Western Digital WD15EADS-00p8b0 with 250GB free space. Network connection seems also not to be the problem. Litecoin client synchronizes days in just a minute with network usage peaks around 24MBit/s. My network connection is 400MBit/s.

It rather seems to be a different issue.
Is there any issue like this known? Is there anything I can find out from the log files or console?

Only messages which look a little bit suspicious (but I don't know if it is related to the behaviour) are the following, which repeat from time to time:

Code:

-2017-06-07 16:07:10 version handshake timeout from 14
-date='2017-05-23 14:15:53' progress=0.999875 cache=124.1MiB(85788tx) warning='1 of last 100 blocks have unexpected version' <- But I see this kind of messages in Litecoin Client also sometimes

Some help would really be appreciated!

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[MtRev]

I'm having the exact same problem. After 3 years of taking a break, I come back trying to sync and it now been 4 days. The program keeps freezing up. Are there any light wallets that use the wallet.dat file?

[BlindMayorBitcorn]

I'm having the exact same problem. After 3 years of taking a break, I come back trying to sync and it now been 4 days. The program keeps freezing up. Are there any light wallets that use the wallet.dat file?

Multibit classic is still available, but the highest transaction fee is too low and the plonkers aren't fixing it. IDK. People will probably recommend Electrum..

[MtRev]

I actually have Electrum installed, but found out it doesn't support wallet.dat

I do have a balance in my old wallet, but having issues syncing.


What's wrong with having a low transaction fee? Isn't this a good thing?

[BlindMayorBitcorn]

I actually have Electrum installed, but found out it doesn't support wallet.dat

I do have a balance in my old wallet, but having issues syncing.


What's wrong with having a low transaction fee? Isn't this a good thing?

Well, not if you want someone to include your transaction in the next block it isn't. The highest you can set it at is .0005 BTC per KB. If that's cool with you, then it's a decent wallet.

[crazyjack]

What's wrong with having a low transaction fee? Isn't this a good thing?

Well if you transaction fee is set to low you will have to wait for a very long time for miners to confirm your transaction. Please check below stated link for recommended transaction fee that will speed up your transaction.

https://bitcoinfees.21.co/

This is taken form above site.

The fastest and cheapest transaction fee is currently 390 satoshis/byte, shown in green at the top.

[MtRev]

Thanks for the fee info. I understand now.

However, I'm still having problems with syncing. Is there a "light" wallet that uses "wallet.dat"?

[HI-TEC99]

Thanks for the fee info. I understand now.

However, I'm still having problems with syncing. Is there a "light" wallet that uses "wallet.dat"?

Not that I'm aware of. However you can install the electrum light wallet, then use the instructions in the quote to export your private keys from your Bitcoin Core client and import them into electrum.

Click file, then receiving addresses. Find the address you sent coins to in the window that opens, right click it, and select copy address. Close the addresses window.

Click help, then debug window.

In the debug window that opens click console.

In the text box at the bottom of the window type

dumpprivkey yourAddress

where yourAddress is the address you sent coins to and copied earlier.

Press your enter key.

The private key for that address should appear in the console window. Copy it.

This is an example private key.

L48toSntMVhC2az4KAQCWscrQGfPbT55yCgzM5cmx9Ao69pTdwrq

Download and install electrum.

https://electrum.org/#download

Import your private key into it using these instructions.

http://docs.electrum.org/en/latest/faq.html#can-i-import-private-keys-from-other-bitcoin-clients

Afterwards your coins should be spendable.

[HCP]

I believe wallet.dat is used only by Bitcoin QT/Core isn't it?

Having said that, you should be able to dumpprivkey (or dumpwallet?) and then simply import the private keys into a "light" wallet like Electrum. You don't need your wallet to be synced to be able to do this... You might be better off "disabling the network activity" by clicking the network icon in the bottom right corner... that should stop the app from being slow and unresponsive while you try to extract the keys.

[MtRev]

I'm getting an error message:
 "Error: Please enter the wallet passphrase with walletpassphrase first. (code -13)"

I guess it's because I have a password attached to it, but I'm not sure how to work the comment now.

I tired:

PASSWORD dumpprivkey ADDRESS
dumpprivkey PASSWORD ADDRESS
dumpprivkey ADDRESS PASSWORD

They didn't work. I tired just the PASSWORD with nothing else, but that didn't work either. Any idea how do to do this, if I have a password attached?

[HCP]

you need to unlock the wallet first...

Code:

walletpassphrase "passphrase" timeout

walletpassphrase "passphrase" timeout

Stores the wallet decryption key in memory for 'timeout' seconds.
This is needed prior to performing transactions related to private keys such as sending bitcoins

Arguments:
1. "passphrase"     (string, required) The wallet passphrase
2. timeout            (numeric, required) The time to keep the decryption key in seconds.

Note:
Issuing the walletpassphrase command while the wallet is already unlocked will set a new unlock
time that overrides the old one.

Examples:

unlock the wallet for 60 seconds
> walletpassphrase "my pass phrase" 60

[MtRev]

Okay, great! I followed your instructions and was able to load it on to electrum.

I do see my past history from back in 2014, but my balance remains zero.
Does it need time to update?

[HCP]

If the icon in the bottom right corner is a green dot, it is synced. if it is a couple of blue arrows, it is still syncing...

The syncing process is generally relatively quick, however it will be somewhat dependent on your internet connection. Having said that, i've not had it take more than a fewminutes to fully catch up a whole wallet after a restore.

Mind you, my history is only a year old... so if you have things going back to 2014 it could take a little longer

[bnhjui]

you can download blockchain and add it to you wallet. you can get it here https://blockchaindownload.nl/ or somewhere else and there is a tutorial how to do it: https://blockchaindownload.nl/en/how_it_works

[HI-TEC99]

Okay, great! I followed your instructions and was able to load it on to electrum.

I do see my past history from back in 2014, but my balance remains zero.
Does it need time to update?

Search for the addresses you think should contain coins at this block explorer website If both your wallet and that site says an address is empty then it's probably empty.

https://blockchain.info/

If you use that site to search for every address that shows in your Bitcoin Core client you might find one that contains coins. Maybe you forgot which addresses you sent coins to after all this time.

[ranochigo]

Okay, great! I followed your instructions and was able to load it on to electrum.

I do see my past history from back in 2014, but my balance remains zero.
Does it need time to update?

It's probably updated. I have a hunch that your Bitcoins may have been in one of the change addresses. Go to Bitcoin Core, Debug Window>Console and then type "listaddressgroupings". This should show you all your Bitcoin Addresses within the wallet, including the change address. Key in each one into Blockexplorer.com and import/sweep those with balance into Electrum.

[MtRev]

Bitcoin address can automatically change? I feel so outdated or just not educated enough about this. This is all new to me

[HI-TEC99]

Bitcoin address can automatically change? I feel so outdated or just not educated enough about this. This is all new to me

That feature's fairly new, it's called a hierarchical deterministic (HD) wallet. Last summer the core dev team merged HD wallet support into core's code. Instead of your wallet generating random addresses it generates a random 128 bit value and uses that to calculate 12 words. The 12 words are called your wallet's seed phrase, and you can use them to restore all the addresses your wallet will ever generate.

Your wallet can generate an almost limitless number of addresses from its seed phrase. Each time you send coins from an address it sends what's left over to a new address to store the change in. Not reusing addresses enhances your wallet's privacy. It makes it harder to figure out which addresses belong to the same wallet.

This is the announcement of the new feature on bitcoin.com.

https://news.bitcoin.com/hd-wallet-support-finally-coming-bitcoin-core/

HD wallets are an important use-case for the bitcoin ecosystem. This is because deterministic wallets don’t reuse bitcoin addresses, which helps with user privacy.

There's an explanation of HD wallets here.

https://en.bitcoin.it/wiki/Deterministic_wallet

[HCP]

Ahhh yes... sorry, I forgot to mentiom to make sure you have dumped the privkeys for your "change addresses".

If you want a shortcut to identify all the addresses in your wallet that contain coins, you can use "listunspent" in the debug console in Bitcoin Core. Make sure you have run dumpprivkey for each address listed as containing a UTXO.

Import those to Electrum and the balance should match up

You can also see all the UTXOs if you turn on "Coin Control"... "Settings -> Options -> Wallet -> Enable Coin Control Features"... then if you goto send and click "inputs" you'll get a list of UTXOs... Change addresses will most likely be listed as "(change)"

[rubikus]

Is there also a way to fix the original problem and use Bitcoin Core?
Or do you all use Electrum or some other light wallet?

[HCP]

I read on another thread that increasing the "dbcache" via the .conf file or commandline arguments can help with performance issues... syncing the blockchain does indeed take a while, it isn't just a matter of downloading 120gigs and you're done... The client has to verify every block which is what usually causes the bottleneck with the CPU etc...

Increasing the dbcache if you have enough RAM can help by reducing the amount of memory swapping while processing everything. Not necessarily a "magic Bullet" but it seemed to help speed things up a little.

[MtRev]

Thank you all for the keeping me informed and helping me get my wallet back in order.

I end up downloading a torrent for the blockchain and all is working again. I now moved everything to Electrum (and I now have a better understanding about HD wallets. thanks!)

[MtRev]

Is there also a way to fix the original problem and use Bitcoin Core?
Or do you all use Electrum or some other light wallet?

I couldn't take it anymore. I downloaded the blockchain via torrent, waiting forever for it to index. Everything was good after.. . so I thought. After 4 days of not loading up the wallet, it took over 24 hours to resync!  I gave in and moved all my coins to Electrum. Even that took forever