Change addresses and wallet backups

[BladeMcCool]

I am wondering how to know if the keys for the addresses that are used to receive the "change" from the transactions are included in my backups? I am concerned that even though I may never create "new" addresses by clicking "new address" in the "receive coins" window, that I may end up sending a transaction and having the change go to an address that is not in my backups, and then suffer hardware failure and lost funds as a result.

I am trying to put my mind at ease without having to make new backups after every single transaction, or sweep funds to an address that I know is in the backups after every single transaction. Any information on the matter would be appreciated.

[Revalin]

https://en.bitcoin.it/wiki/Key_pool

[CIYAM]

By default the "key pool" is 100 and assuming every send you do requires a change address then provided you had backed up around 100 tx's prior to your current one then they will all be able to be recovered.

[Dabs]

To be really safe, do a backup after every transaction. After every 100 transactions is less often, but if you forget, the 101st transaction can end up costing you all your coins. If you make a successful backup after that, then you have a good backup for the next 100 transactions.

I personally make a backup after every 50 transactions, and it gives me room to forget and make another backup at 51 to 99 transactions.

After several hundred transactions, or whenever I feel like it, (maybe below 1000), I'd just consolidate all my coins and send them all to a brand new wallet.

[CIYAM]

I also pretty much do a backup after every tx - I also save my source code after every line changed and do git pushes generally after every commit.

[Dabs]

A daily backup is only 365 files for a year. If your wallet is about 1 megabyte, that's only 365 megabytes. All files older than that, you can safely discard.

My office computers have this little scheduled task that backs up important work files every middle of the day, to another computer in the network. I don't even have a "server", they just back up to each other.