wallet.dat file need periodical backup? or just one time?

[wsxdrfv]

wallet.dat file is important,

1. so is it enough to backup it just once?

2. or should it be backup continuously?

I think 1 is right. Is this right?

[ranochigo]

Depends on when you've created the wallet. If you've created the wallet (not restore) recently, then you probably just need one. If it says HD at the bottom right, one backup is enough, unless you change or set a password.

If you've created the wallet a long time ago and the bottom right doesn't have the HD symbol, you need to backup per 1000 or 100 transactions, depending on your configuration.

[Xynerise]

Any time a change is made to the wallet a new backup is required (and as always, its smart to have your private keys saved as well.)
MEANING: You encrypt your wallet / change your password or you receive new coins, new back up needed.

You don't need to backup your wallet once you receive coins if it's a HD wallet.
Also backup of wallet is the same as backing up your p private keys.

[rpstatic]

One backup is not always enough. The first time you start your qt wallet it will create about 100 addresses with private keys for you, but only one of it will be visible.

If you then encrypt your wallet, the reserved addresses are flushed and new ones will be generated. So it's important that you backup your wallet again after you have encrypted it! Otherwise you don't have your private keys from newly generated addresses.

[ranochigo]

One backup is not always enough. The first time you start your qt wallet it will create about 100 addresses with private keys for you, but only one of it will be visible.

The keypool has been increased to 1000. The wallet maintains the keypool at 1000 as long as your backup is from a recent version of Bitcoin Core. It's generated every time the wallet has been unlocked. You can back it up whenever you want and that backup will be valid for 1000 transactions. The general consensus is to back it up every 100/1000 transaction since your addresses will definitely be used up by then.

[rpstatic]

One backup is not always enough. The first time you start your qt wallet it will create about 100 addresses with private keys for you, but only one of it will be visible.

The keypool has been increased to 1000. The wallet maintains the keypool at 1000 as long as your backup is from a recent version of Bitcoin Core. It's generated every time the wallet has been unlocked. You can back it up whenever you want and that backup will be valid for 1000 transactions. The general consensus is to back it up every 100/1000 transaction since your addresses will definitely be used up by then.

Do you know in which version they changed it? Recently I tested a few altcoin wallets and the daemon always states something like generating address 1 .. 100.

So, OP, just be careful and backup the wallet file from time to time.

[ranochigo]

Do you know in which version they changed it? Recently I tested a few altcoin wallets and the daemon always states something like generating address 1 .. 100.

It was changed in v0.15.0[1]. Most altcoin wallets are always behind Bitcoin and its not a significant change anyway. If you want, you can increase or decrease the keypool by running it with a flag.



[1] https://bitcoin.org/en/release/v0.15.0#performance-improvements

[MrCrank]

wallet.dat file is important,

1. so is it enough to backup it just once?

2. or should it be backup continuously?

I think 1 is right. Is this right?

What wallet do you use Bitcoin Core or Electrum?
I think need save all private keys, this is easy to use..

[cellard]

My wallet is from the old Bitcoin-QT days so I assume originally it was a backup-every-100-generated-keys one. The "HD" sign in the lower right of the window is still greyed anymore, so I assume it still is the case and I need to make backups every 100 newly generated addresses.

In any case I always make backups after a decent amount of generated addresses and I never delete wallet.dat files, just rename them and put them somewhere. I can't be bothered to create a new wallet and send all of my coins over there, not looking forward to paying the fees even with the mempool now at cheap prices. Just keep making backups as you should anyway and you'll be ok. If anything this forces you to not get lazy on the backup game.

[kantoi]

In addition to backing up the wallet frequently I am storing my private keys of all addresses at secret places. You might want to do that too...

You could also write a little bat file to copy all your wallets.