If you are using the latest Bitcoin Core, then you should make a new backup every 1000 addresses. That is the default keypool size and you should make a new backup whenever the keypool runs out. This should be done regardless of HD or non-HD wallet, and even more so because you are using addwitnessaddress.

Also, you will need to unlock your wallet every 1000 addresses so that the keypool can be refreshed.

You should keep making backups regularly. What HD wallets do is that you can still use old backups and still generate the private keys that are not in the keypool at the time of backup.

The wallet contains a field which has the latest block height that the wallet is synced up to (as in it has the transactions for the wallet up to that block height). So when restoring, Bitcoin Core will know where it should begin rescanning the blockchain to get any new transactions.

Because OP is also using addwitnessaddress, older backups will not know about those witness addresses (the scripts themselves must be added to the wallet) and addwitnessaddress will need to be called again on every single address generated.

Im not sure if your method would work. You should ask achow first in my opinion. Here's a guy that was trying to do something similar:

https://bitcointalk.org/index.php?topic=2107760.0

And here gmaxwell said that you shouldn't mix BTC addresses and segwit addresses within the same wallet:


Honestly I would wait until 0.16 to deal with segwit. I think they will allow you to manage several different wallets at once, so you can have a legacy wallet and a segwit wallet and change address will automatically be segwit in the segwit wallet or something along the lines.

Im too paranoid to use segwit until I have it isolated in another wallet and there's proper GUI support.

But where are you choosing what address you want to use to recieve the change of the address? You may be able to choose paramater 5 (which is not substractfeefromamount but subtractfeefrom  followed with the address):



But I still don't see any command that lets you specify what address you want to receive the change at?

How do you specify what address in sendmany will be used as a miner's fee?


The point of sendmany was to allow several recipients (to send to different addresses at once from a single input) but I dont see where it lets you specify what address is going to be used as a fee.

I would be sure to know what im doing before doing anything of this nature.

Because segwit wallet support is not fully implemented in Bitcoin Core, all addresses generated (including change), will be non-segwit addresses. Although it is capable of converting a non-segwit address into a segwit address for you to receive it, the wallet will not do that automatically for change addresses.

Hi,

I am running a service that accepts user deposits and sends withdrawals. I am using Bitcoin Core for the wallet.

I'd like to go full-Segwit with my service, but here's the problem: bitcoind wallet does not generate P2SH-P2WPKH (Segwit) change addresses by default. So even if I generate P2SH-P2WPKH addresses to accept deposits from my users via addwitnessaddress, whenever I send coins, the change is going to a P2PKH address.

I could manually create a P2SH-P2WPKH change address by (in pseudocode):


No the thing is that addwitnessaddress(chaddr) breaks things a little since the resulting address is added to account addresses, and is NOT marked as a change address. Therefore it is used as a regular account address and generates send/receive transactions. It looks like it does not break anything except creating additional transactions returned by listtransactions and inaccurate "amount" fields.

So, a solution I'd really love to see is:

1. make the wallet generate segwit change addresses by itself so that we can just use sendtoaddress and other RPC calls without workarounds (maybe an option in config?),
2. somehow make the address resulting from addwitnessaddress(chaddr) as a change address,
3. or allow getrawchangeaddress to generate P2SH-P2WPH address in the first place.

Obviously (1) would be much better, but at this point I am looking for any solution that would "just work" and not break my workflow.

Cheers and thanks,
Ethan

Not sure about the fee, and not sure what the current behavior for change should be may you use a segwit address without specifying a change address.. so to guarantee that you get your bitcoin's change back in a segwit address, simply create a receiving segwit address and enter that address in the options (see "custom change address"), after enabling "Coin Control" feature:

https://bitcoinspakistan.com/files/2014/03/coin_control_enabled.png

This way you will do exactly what you want to do.