Bitcoin Forum

Hello,

I'm running on an old laptop with 512 MB RAM and other low specs, I could just about use the Bitcoin client as the only program running until a while ago when my HD died and I replaced it with a USB memory stick. So now memory swapping is really slow etc.. and I am more or less unable to use the standard bitcoin client. (almost completely freezes my system and block chain updating is so slow it would take me weeks to update.. rendering my machine unusable all that time too)

Soo. How can I get at the bitcoins stored in my wallet.dat?

Is there another client with better performance that is compatible? (I'm on Ubuntu linux)

Failing that, how can I extract some bitcoins and put them in an online wallet without using the client?
(though I'd rather not be using a third party service..)

1. download bitcoin-tools(python wallet-reader)
2. export the privatekeys.
3. import them, at a wallet site(mtgox, blockchain.info ...)
4. ???
5. profit!

Thanks =)

You can also download an up-to-date blockchain here: http://eu1.bitcoincharts.com/blockchain/

If you can't run the standard client on your computer, you will likely have a hard time running another full client. Beyond that, even if you could run a different client, you would need one that could import a standard wallet.dat file. I don't know which available client fits that bill, if any, but you can check the Alternative Clients section of the forum for some options. (If Electrum has a Linux version, it may work, as it's a "thin client.")

Barring that, you can still get at your private keys so you can import them into an online wallet. Look through the forums for Pywallet, a Python-based toolkit that can extract your private keys from your wallet for you. It's not the easiest thing to use, but should do the job.

Blockchain.info stores your private keys locally but writes an encrypted backup to their host:
 - http://www.blockchain.info/wallet

Thanks guys, I've just used pywallet and now imported my keys to blockchain.info ;D

I'll now celebrate by purchasing the first edition of the bitcoin magazine!

Ok, I guess I'm stupid, but after doing this and when trying to send some bitcoins with blockchain.info it's asking for a private key to send from a particular address. But I thought what I just imported was the private keys?

??? explain please...

I ran
./pywallet.py --dumpwallet
this exports some json which I assume is my wallet private keys?

I then created a wallet on blockchain.info, went under import/export, pasted the json there and imported it...

So now my balance is showing up fine on blockchain.info

But then I go on to "Send Money" (on blockchain.info), put in a "To" address and an amount, click "Review Transaction", and I get this screen:

https://i.imgur.com/YeiK7.png

And I'm not sure why this is appearing, or what I need to put there. Did I go wrong at some stage and only import the public keys?

no the stuff from --dumpwallet is a full dump of the wallet(and not only the privatekeys).
if you have an encrypted wallet you should use --password=YOURPASSWORDHERE too.

you can grep it for "sec" to get the privatekeys.

I'm a little surprised that no one has created a simple, small program by now that just reads the wallet.dat file and spits back out a simple text file of the private keys, in the desired format (hex or whatever format starts with '5'.)

If anyone else thinks that that would be of use I might see how hard it is to do. If the file format is readily available and not too complex, it shouldn't take too long to whip something up.

Multibit and Armory aren't close enough?

He said simple and small, and I know for a fact that Armory isn't going to run on a box with 512mb of RAM. Not sure about multibit though.

I think one problem may have been I used an older version of pywallet... there seems to be two versions. I tried what I think is the latest and this time some private keys at least showed up then in the export page on blockchain.info. However in that case the balance shown was far smaller than it should have been... ???

Anyway, I've dug out another PC that seems to work a bit better and will copy my wallet across and update on that. Then send my coins across to an electrum install or something.

there are probably a few addresses that the coins are spread over, so you would need to import all their private keys

Another computer is easier, if that fails, ask someone you trust to use your wallet to send the coins to a different address that you can access (blockchain.info or mtgox for example)