How to Backup Wallet

[wings]

Can someone please tell me how to backup the bitcoin wallet?

I see the files, directories, address books, but I am not sure where the wallet is?

thanks,

-W

[Gavin Andresen]

Copy the wallet.dat file somewhere safe and secure.
To be 100% belt-and-suspenders safe, shut down Bitcoin before doing the copy.

wallet.dat is:
  Linux/unix:  ~/.bitcoin/wallet.dat
  Windows: %APPDATA%\Bitcoin\wallet.dat  (I think; I don't run Windows)
  Mac: ~/Library/Application Support/Bitcoin/wallet.dat

[sentry360]

Just to make sure, being new to Linux it took me a minute to figure out what to do to get some result. What I did is:

cp ~/.bitcoin/wallet.dat walletbackup.dat

Is this file an effective backup of my wallet?

[theymos]

Yes. But make sure you stop BitCoin before doing that.

[Inedible]

You'll want to make sure that wherever you copy it to, no-one else can get access to it.

[FreeMoney]

I am not 100% clear on this and would like someone to explain.

I read that you can have problems if you backup, spend some, and then load the outdated backup. This is because you will have the key to the already spent coin, but not the key to the "change" that was generated and is not in your backup. So you need to redo the backup after every transaction or risk having unspendable coins.

I think a solution to this would be to have a "savings account" that rarely receives transfers and always keep a backup of it. And have a "spending account" that you wouldn't be devastated to lose.

[Inedible]

I am not 100% clear on this and would like someone to explain.

I read that you can have problems if you backup, spend some, and then load the outdated backup. This is because you will have the key to the already spent coin, but not the key to the "change" that was generated and is not in your backup. So you need to redo the backup after every transaction or risk having unspendable coins.

I think a solution to this would be to have a "savings account" that rarely receives transfers and always keep a backup of it. And have a "spending account" that you wouldn't be devastated to lose.

To keep it simple, you could think of it like backing up your email folder. I you backup, send some email and then restore your backup, you're not going to have your newly sent email.

Why you'd want to spend your coins and then restore a backup is beyond me (except for fraud reasons but someone committing fraud wouldn't be asking on a public forum).

I believe the more accurate answer is because BTC are spent in the chunks they came in.

E.g. you have 150 BTC which were generated by you. This gives you 3 x 50BTC chunks.

You decide to spend 125BTC on something super shiny. All 3 of your chunks get spent BUT 25BTC are returned as change.

Your wallet now has new data saying, all 3 chunks were spent but you now have a new 25 BTC amount (your 'change' if you will).

If you overwite this wallet, the system will know you've gotten rid of the 3 chunks (of 150BTC) but it won't have the new key for your 25BTC change, thus you lose it all (except you still have your super shiny).

That's my understanding of it - can someone more experienced confirm?

[FreeMoney]

Why you'd want to spend your coins and then restore a backup is beyond me (except for fraud reasons but someone committing fraud wouldn't be asking on a public forum).

 

Um, am I confused? You would restore your backup because you lost your wallet. So I backup, spend, loose my wallet. The backup is not reliable, I don't have any change keys.

I have to back up the wallet after every transaction, sent and received.

I just thought of another possibility. If I know I will never be using smaller units than .1 BTC I can churn my balance until it only contains tenths. Now I backup and can spend in increments of tenths without needing to make a new backup. Bleh, until someone sends me a 50. Does anyone know if I have a 50 and 3000 tenths if it will always use the tenths first? It ought I would think.

[rahl]

Really seems like the client should have an option to automatically backup the wallet after every transaction if this is the case ehh...

[Maged]

Really seems like the client should have an option to automatically backup the wallet after every transaction if this is the case ehh...

This thread is extremely old. Since then, we've implemented the creation of a pool of 100 (by default) pre-generated keys that your client will use. That means that a backup won't expire after each transaction anymore. However, you still need to do regular backups.

Note: there is currently a bug where the pool won't be created in a new wallet until a few transactions are made.

[lonestranger]

Boy, I'm really trying to follow the instructions here, but I can't even find a wallet.dat file on my system. I recently started using ubuntu 10.04 (like it), but linux is a daily learning challenge.  Where is wallet.dat?

[bitlotto]

Boy, I'm really trying to follow the instructions here, but I can't even find a wallet.dat file on my system. I recently started using ubuntu 10.04 (like it), but linux is a daily learning challenge.  Where is wallet.dat?

In the file browser make sure to set the option to see hidden files. The wallet.dat is in the ".bitcoin" folder.

[thinkweis]

I made a page on my site dedicated to creating a secure bitcoin wallet using a thumb drive. Even if you've never used Ubuntu before this tutorial will make it very easy for you. It includes detailed instructions on every step of installing Ubuntu and securing your wallet. Includes screenshots.

http://startbitcoin.com/how-to-create-a-secure-bitcoin-wallet/

If this was helpful to you, please donate. 1HbdRpinMDQ2cgUWsKiMPDN2icC8rNpS1i

-Think

[sprawl]

The Bitcoin Wiki has a page on backups: https://en.bitcoin.it/wiki/Backup#Backup

I wrote my own script (instead of searching and using an existing script ) for regular and automated backups: https://github.com/hreese/Bitcoin-Wallet-Backup

[Blackout]

This backup does not make sense....

if you make and exact backup of your bitcoin wallet, as far as I can tell, it is only good for use if your original wallet never gets into trouble.

If some virus or phishing or just someone on your computer gets access to or spends the bitcoins in the original wallet - you are f&^cked. Hence?  What is the point of this backup? You will load the back and it will be invalid and the coins will be gone.

I think the only true backup is to make a NEW bitcoin wallet install on a thumb drive and encrypte it and disconnect it from the computer most of the time unless you need access to your coins, and then send your bitcoins to that separate wallet from your main wallet - so you have an operating wallet that you keep a few coins in, and then your savings wallet that is not connected to the internet.  Perhaps you backup the saving wallet just incase the usb drive goes bad or something... but other than that backup up your bitcoin wallet is useless unless I am blind and missing something here.

 

[error]

Backing up the wallet.dat file is meant to protect you from losing coins due to Windows eating itself, your hard drive dying, reinstalling Windows etc. The usual stuff that Windows users have to put up with. It won't necessarily protect you from having the file stolen. (Though if you know or suspect it's been stolen, you can always try to send the coins before the thief does.)

[Blackout]

That's what I figured.

How do you make a NEW wallet though?  Does it have to be on a different machine?

I tried to install the new client to a thumb drive but when I opened it up it was still my same old wallet, not a new one.

[jackjack]

Either rename wallet.dat to something else so bitcoin makes a new wallet.dat, or use my bitcoin fork with --wallet flag

[JoelKatz]

I have to back up the wallet after every transaction, sent and received.

You do not need to backup the wallet just because you received money. Receiving money doesn't involve actually doing anything on your part other than updating your balance number.

[Blackout]

Either rename wallet.dat to something else so bitcoin makes a new wallet.dat, or use my bitcoin fork with --wallet flag

Can you elaborate how this works a little more?  If I install bit coin on a thumb drive it is still going to use the
wallet.dat in my users dir on win 7?  So I have to rename that walletsavngs.dat and then it will make a new one with no coins in it?

then how do I transfer some of the savings to the new one... I just want to make sure I don't screw things up and end up losing my coins, not that I have a gigantic amount but I figure better to understand this now rather than screw things up royally later.

I really wanted to just have an encrypted whole version on a thumb drive... does it ALWAYS place the wallet.dat file on your local machine? meaning you can't just walk around with your wallet all on your thumb drive without a machine
and say, then go use it somewhere (like you would a regular cash wallet)

My idea is to have several high grade flash drive wallets and keep one on a key chain so if I was sitting at an internet cafe or something that accepted bitcoins I could do it... more places in NYC are starting to take them.... but how do you do it if you're not home?  I don't want to use some third party service either....  I'm thinking you have it on a thumb drive encrypted with a password but I'm not sure how to go about doing this.

Some say never put your wallet into another machine but then how would you have bitcoin currency on you without carrying around a laptop or something?  I imagine having an amount that you need to use would not be a big risk just as you can't live your life in fear of having cash in your wallet that you're going to get mugged.  You carry the appropriate amount of cash you need in your wallet you don't usually carry your life savings around with you... 
some people are debt card crazy but I don't like banks and companies knowing every god damn ting I do and then marketing to me and tracking me... it's annoying... this is one of the things I like about bitcoin.