Bitcoin Forum

I have a new computer and I'm trying to figure out how to move my bitcoin wallet over to this new machine. How can I accomplish this?

https://en.bitcoin.it/wiki/Securing_your_wallet#Locating_BitCoin_s_data_directory

Copy the wallet from that directory on the old computer to the new one, then run the bitcoin client with the -rescan switch.

For anyone googling this in the future - note that the -rescan switch was added in the 3.20 client, I ran into problems when I was working with two wallets because I was using the 3.19 client and trying to use -rescan.

For older clients you need to delete blk0001.dat and blkindex.dat, and let it redownload the block chain...

Do people ever transfer BTC by just mailing someone a wallet.dat?

You'ld want to encrypt it first -- using TrueCrypt, for example, and then send only the encrypted archive:
  http://en.bitcoin.it/wiki/Securing_your_wallet

Is it true, that nowadays (after version 0.3.2), you can just copy the wallet to the new location - without --reindex or deleting the bulk datas?

You'll want to just copy the whole Bitcoin data directory with the wallet.dat and subdirectories, so you don't have to download the blockchain again.

And what should I do if i have a webserver and want to keep the offline time low? I cant wait until some GB are transferred between the server.. Or is there no other stable possibility?

Just closing bitcoin, copying the wallet.dat (after moving but not deleting any previous important wallet), and restarting with the bitcoind -rescan option is sufficient to move a wallet to another machine. If you don't already have a blockchain downloaded, it will be a long time before that bitcoin is ready though; copying an existing complete 12GB datadir can save a day of re-downloading and processing the blockchain.

I can't think of many scenarios outside of restoring a backup where you'd put an existing wallet.dat up on a server.

use online wallet

You could also just transfer the coins to a new wallet on the new machine.

Its because of a migration to a bigger server. And I need the wallet because there are multiple "user accounts" inside...
How long does it take to rescan in general?

About 10 minutes on a normal wallet and PC. Longer for many addresses in the wallet and on a slow CPU. You don't need to rescan as long as there is no chance that wallet received payments while it was "down".

Ah, i see - thanks a lot!