You are likely to have problems with missing payments as you start one client, and it updates the blockchain and finds all the transactions for it's wallet. Then you start the other client and it updates the blockchain more, and only finds payments to it's wallet, ignoring any payments for the first wallet. You could put the command line -rescan option into the startup for each bitcoin to look for missing payments when bitcoin starts up. You definitely wouldn't want a chance of both running at the same time.
The best solution to not hit the network twice for everything is to have the second bitcoin on a different machine use the connect=192.168.1.xxx bitcoin.conf option so it only connects to the first client on your network.
The database log files can have private key data written into them. They are cleared when bitcoin shuts down, but if bitcoin is just aborted, they can remain.
Thanks a lot deepceleron! Funnily enough, throughout all my research googling and learning about bitcoins, your name has popped up in many of the threads matching my search terms dating long back - you have indirectly helped me more than you think ^^
Anyway, I have a new idea for my setup, does this sound ok?
- I create 2 wallets, and back them up to my encrypted container stored on dropbox.
- I create a second encrypted container to store my datadir.
- When I want to swap between the two wallets, I ensure bitcoin.exe is completely shut down, I then proceed to delete all files in the datadir except: wallet.dat, blk0001.dat, blkindex.dat andbitcoin.conf.
- I then replace wallet.dat with the other wallet, and rerun bitcoin.exe (always with -rescan) on a new Tor identity.
I really want to avoid having a second computer or second database
Also, a hypothetical question as there is something I am unsure about in regards to the wallet.dat file: If I create an offline backup of my wallet.dat on day 1, can I restore that day1 wallet.dat 500 days later after plenty of usage of my wallet, and still be fully functional with all my bitcoins? Or do I always have to have an "up-to-date" backup of my wallet.dat?