Let me make absolutely sure I understand correctly.
So if I encrypted a wallet with a keypool size of 100.
Copied the encrypted wallet and decrypted the copy.
Started bitcoin-qt with the copied wallet and the keypool=500 command.
Sent coins.
Deleted copied wallet.
Then my encrypted wallet still has the private keys to all my coins? (assuming it already had plenty of spare keys)
Thank you for you time and for promoting my sanity,
BookLover
Yes. However I would recommend against "playing around" with money given that my understanding could be incomplete.
In your example backup A had 100 keys in keypool, you then added 400 new ones, then used the oldest one. The keypool is actually a key queue the keys are used in sequential order.
So even if the current copy was lost "backup A" cointains the "used" key plus 99 more.
Still as CIYAM indicated anytime you make changes to the wallet I would strongly recommend making a new both before AND after the change. I would also strongly recommend you backup system be automated AND not replace prior backups (i.e. have date of backup in filename). A decent sized keypool combined with good backup procedures should make the risk of key loss negligible. If you are still paranoid using pywallet you can dump the keys from the keypool and print them out as an alternate backup method (would allow recovery even if wallet became corrupt and backups corrupt as well).
I even have them named by date.
