New coins from old backup wallet.dat what gives?

[Blackout]

Ok so I regularly backup my wallet.dat and I also have some other wallet.dat savings where I created a new wallet and sent it coins then offlined it.

Since I spent a bunch of bitcoins lately by wallet was at 0 so just out of curiosity I renamed the wallet.dat backup.wallet.dat and then grabbed my last backup when I had like 25 btc in it

The 25 btc are there? What gives?

It's the same wallet key just a backup should this not be.. I should still see 0 right?

And no, this is not one of my savings wallets with transferred money this is just a daily backup before I spent the 25.

[1714053846]

1714053846

[defxor]

Ok so I regularly backup my wallet.dat and I also have some other wallet.dat savings where I created a new wallet and sent it coins then offlined it.

Since I spent a bunch of bitcoins lately by wallet was at 0 so just out of curiosity I renamed the wallet.dat backup.wallet.dat and then grabbed my last backup when I had like 25 btc in it

The 25 btc are there? What gives?

It's the same wallet key just a backup should this not be.. I should still see 0 right?

And no, this is not one of my savings wallets with transferred money this is just a daily backup before I spent the 25.

It's likely just tricking you, not understanding the keys it has have been used from another copy. Run the client with -rescan

[helloworld]

Even if it shows 0.25 it's a dupe... so it'll just go to nowhere if you try to spend it... the network will see it as a double spend and it'll be unconfirmed forever.

[Blackout]

Not .25  25 btc.

I thought maybe the network needed to just update the blocks.

I don't understand the point of backing up wallets then.. say I backup my wallet everyday, or week or whatever,
but between the last backup and the latest, I have spent some coins... and then my computer blows up
and I install the last backup...  I thought the network was supposed to detect my key and automatically bring me back to the proper amount of coins I should have... if it just give me an invalid wallet... isn't this just as bad
as losing all your coins?

I don't get it.  This is why I tried this only when I had 0 coins... I figured it might initially show the last coin account from the backup wallet but then update itself through the network to the real amount of coins that specific wallet key is supposed to have?  Isn't that how it's supposed to work?

Am I doing something wrong?  Note these are not two separately created wallets - I have those.. this is the same wallet, just a backup of a day earlier.

[defxor]

Am I doing something wrong?  Note these are not two separately created wallets - I have those.. this is the same wallet, just a backup of a day earlier.

The Bitcoin terminology is the problem. They're not wallets, they're keyrings with a lot of keys. Initially your keyring gets populated with 100 keys, all able to unlock 100 vaults. Whenever you use one key, another one gets added (and none removed) from your keyring.

Thus even your oldest backup contains the keys to the next 100 transactions (=vault contents) you do. That the client can become confused when you start switching keyrings back and forth is not a problem - just run -rescan.

[Gabi]

Not .25  25 btc.

I thought maybe the network needed to just update the blocks.

I don't understand the point of backing up wallets then.. say I backup my wallet everyday, or week or whatever,
but between the last backup and the latest, I have spent some coins... and then my computer blows up
and I install the last backup...  I thought the network was supposed to detect my key and automatically bring me back to the proper amount of coins I should have... if it just give me an invalid wallet... isn't this just as bad
as losing all your coins?

I don't get it.  This is why I tried this only when I had 0 coins... I figured it might initially show the last coin account from the backup wallet but then update itself through the network to the real amount of coins that specific wallet key is supposed to have?  Isn't that how it's supposed to work?

Am I doing something wrong?  Note these are not two separately created wallets - I have those.. this is the same wallet, just a backup of a day earlier.

Every transactions is logged in the blockchain. So, everytime you use the bitcoin client it check the private keys in your wallet with the blockchain and find your bitcoins.

If you spent that bitcoins then try a -rescan

As for regularly backupping it, the problem is that if you use a different address everytime then your wallet will contain more private keys. If your backuped wallet is an OLD one, it may not have the new keys. So, if you lose your wallet and you use the backuped one, it doesn't have the recent keys and you lose the BTC attached to these recent keys. A bad thing

[evoorhees]

Run the client with -rescan

This "-rescan" thing is awful. I'm a bitcoin enthusiast, and have spent many hours learning how it works from a variety of perspectives. Yet, I have zero idea what "-rescan" is, why it's necessary, or how to do it.

This is the kind of thing that totally confuses and puts off average people. If this function is important (and I assume it is because I've seen it mentioned quite a bit on the forums) then the official client should enable it as an easy option, with a friendly explanation. Perhaps the devs are already working on this?

In any case, two versions of a wallet file should not show differing balances. These things which are confusing for enthusiasts are show-stoppers for the public.

[Blackout]

Oddly it suddenly fixed itself on it's own without a -rescan

This was NOT an old old wallet.. just a few hours prior to spending 25 btc and I just wnted to see how it would handle it and figured it was better to experiment when I had no coins in the wallet than to experiment when i did.

Now it appears back to normal and has just some newly mined coins in it.... the spent 25 vanished but for a bit it looked like they were there.

[defxor]

This "-rescan" thing is awful

Absolutely agree. What it does is "verify that what my wallet thinks is actually true" by going through the transaction blockchain.

This was NOT an old old wallet.. just a few hours prior to spending 25 btc

"Old" = not the up to date one.

I think you'll find it easier if you use the keyring+vaults metaphore instead (since that's what it is). Your wallet never "contains" bitcoins.

[joulesbeef]

I despite the term wallet for the bitcoin keyring, for the specific reason that it misleads people into how it all works.

thinking of it as a wallet, would have people backing it up after each transaction, to keep it up to date.. instead of backing up every 75-90 keys(sorry i dont want to get close to 100 without an updated backup)

I only have one real world wallet, if it gets stolen i lost what it contains, but it can only be used by one person at a time.

now if my real world keys get copied, people can come in my house at any time and steal my stuff, and many people can use the same keys at a time(of course they can only use the coins once)


so yeah, it isnt a wallet, it is a key, your coins arent on your pc they are on the blockchain.. i wished one of the alternative coins would have changed that at the very least.

[JoelKatz]

I don't understand the point of backing up wallets then.. say I backup my wallet everyday, or week or whatever,
but between the last backup and the latest, I have spent some coins... and then my computer blows up
and I install the last backup...  I thought the network was supposed to detect my key and automatically bring me back to the proper amount of coins I should have...

You're focusing on something that isn't the issue. The issue is whether or not you can spend your coins by any method. The reason for the backup is to make it *possible* for you to recover your coins.

if it just give me an invalid wallet... isn't this just as bad
as losing all your coins?

Is dropping $100 bill on your floor as bad as having it burned to bits? No. The former is easily recoverable. The latter is fatal.

I don't get it.  This is why I tried this only when I had 0 coins... I figured it might initially show the last coin account from the backup wallet but then update itself through the network to the real amount of coins that specific wallet key is supposed to have?  Isn't that how it's supposed to work?

You are focusing on an irrelevant detail. What matters is whether it's possible for you to recover the coins. The cosmetic issue of whether it takes an extra step or two is minor.

A backup wallet backs up your keys. With your keys, you can spend your coins. You are not screwed, and that's what is important.

[Blackout]

So what is the frequency of which you should backup your keys in your wallet.dat file?

Is a key used for every transaction?

So if you have gone past 100 transactions and you have an old backup - it's usless because you have gone beyond those keys?

Am I getting this now or no?

[defxor]

So what is the frequency of which you should backup your keys in your wallet.dat file?

Is a key used for every transaction?

So if you have gone past 100 transactions and you have an old backup - it's usless because you have gone beyond those keys?

Am I getting this now or no?

The default client generates a new key for every transaction, yes. However, the old keys are still the ones opening the vaults to the transactions they were part of - so it would only be "useless" for transactions using newer keys that weren't there when you made that backup. Of course, newer backups would take care of those as well.

Personally I use a tool that makes new encrypted backups whenever the wallet file changes (=new transactions/keys), and I can travel back in time to any previous wallet version.

The official client could indeed explain how this works in a better way.