Help me understand how private keys work in wallet.dat

[BusyBeaverHP]

I just opened Bitcoin Core in CMD with bitcoin-qt -keypool=10000. The time it took from launch to UI, with regard to the 10,000 key pool, wasn't noticable.

How do I verify that my wallet has 10,000 keys in its pool? Should I notice an increase in the my wallet filesize?

It should be noted that I opened Bitcoin Core with an existing wallet with roughly 0.16 BTC in it.

So did this expand my existing wallet's keypool to 10,000?

[DeathAndTaxes]

from the debug console type getinfo to get some stats including the number of keys currently in the keypool.  I forgot that if your wallet is encrypted the client will wai until the first time you unlock it (like sending coins) to expand the keypool.  You can force the wallet to unlock to generate the additional keys now.  You can do that from the debug console as well with walletpassphrase <your passphrase> <time to remain unlocked>.  I would set time to remain unlocked to something like 600 seconds to ensure sufficient time to generate all the keys.   Once it completes you can lock the wallet early if neccessary with lockwallet IIRC (type help in debug console to verify exact command).

[DannyHamilton]

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I forgot that if your wallet is encrypted the client will wai until the first time you unlock it (like sending coins) to expand the keypool.
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This is new behavior in 0.9.x right?

[DeathAndTaxes]

- snip -
I forgot that if your wallet is encrypted the client will wai until the first time you unlock it (like sending coins) to expand the keypool.
- snip -

This is new behavior in 0.9.x right?

I think it has always been this way as it doesn't write unecrypted keys to an encrypted wallet.  Without the wallet passphrase that is what it would have to do in order to expand the keypool.

[DannyHamilton]

- snip -
I forgot that if your wallet is encrypted the client will wai until the first time you unlock it (like sending coins) to expand the keypool.
- snip -

This is new behavior in 0.9.x right?

I think it has always been this way as it doesn't write unecrypted keys to an encrypted wallet.  Without the wallet passphrase that is what it would have to do in order to expand the keypool.

Duh.  I really didn't think that one through.  Thanks.