Backing up to USB

[mlipscombmtl]

I guess this is a pretty simple question, but before I go ahead and do this I want to make sure I know what I'm talking about.

I have a BTC wallet on a computer and wish to remove it (completely, as in uninstall it,) and back up my bitcoins to 3 usb drives (I will keep a few on my phone, but the rest of my coins I want stored offline and to be unavailable.)

When I go to my wallet there's a "back up wallet" option under file, which once initiated leaves a .dat file on my desktop. Now what I want to know is, is that .dat file a full back up of my bitcoins? In other words, if I put that .dat file on my usb keys, can I then uninstall my wallet completely and be able to recover my bitcoins in the future from my usb keys? Also, if someone stole my computer, would they be able to somehow re-install my wallet and have access to my bitcoins? My goal is to hide my coins and permanently make them unavailable from my computer. Am I missing something here? Please confirm. Thanks in advance!!!

[shorena]

Yes this .dat is all you need. https://en.bitcoin.it/wiki/Wallet

Yes, if your PC is lost/stolen/etc. and the "new owner" knows what to look for there is a chance the file might be recovered.

If you want to be sure, overwrite the harddrive after you exported and copied your wallet.

Edit: if you dont want to erase your whole harddrive, there is a tool called "Eraser" which can overwrite certain files to make sure they can not be recovered.

http://sourceforge.net/projects/eraser/

[mlipscombmtl]

That's great, ok, one more question, how to you re-install you bitcoins from a .dat file?

[shorena]

Install on new PC find the wallet.dat and replace it with your old one.

Here is a good step by step guide: http://bitcoin.stackexchange.com/questions/10974/import-wallet-dat-into-a-new-bitcoin-qt-client

the -rescan part is outdated afaik

[mlipscombmtl]

Ok,, so just to be 10000000% sure, I'm going to export my .dat file, hide it on a few usb keys, then delete my bitcoin wallet, and write over my drive. There is no chance I will lose my btc....right? Right, ,this has been confirmed but I'm still nervous about it!!!

[shorena]

Ok,, so just to be 10000000% sure, I'm going to export my .dat file, hide it on a few usb keys, then delete my bitcoin wallet, and write over my drive. There is no chance I will lose my btc....right? Right, ,this has been confirmed but I'm still nervous about it!!!

Well dataforensics is very complicated. Sometimes people tell you they can recover everything no matter what you do, but i doubt that. The most realistic information about recovering data I read was: 75% chance to recover a single bit (if overwritten once with random data). So to get a single 7-bit ascii letter right you must have those 7 bits correct, chance for that is .75^7 = 13%. Your wallet.dat has probably >1kb so the chances are very slim to recover those data.

If I may suggest another option: Create a new wallet first and transfer the BTC there, that way you dont have to trust anything or anyone. You might have to pay transactionfees though. But you are 100% sure that your old wallet is empty and you dont have to care if someone can restore it. On the other hand you seem to have some kind of backup in mind (since you are using 3 usb sticks)

[mlipscombmtl]

My friend suggested that once I've deleted my wallet to use the drive wiper feature in cc cleaner and set it to 3 passes, that should do it, do you agree?

[hilariousandco]

Ok,, so just to be 10000000% sure, I'm going to export my .dat file, hide it on a few usb keys, then delete my bitcoin wallet, and write over my drive. There is no chance I will lose my btc....right? Right, ,this has been confirmed but I'm still nervous about it!!!

I'd check your wallet.dat isn't corrupted and works in another client before you rely on it as a backup.

[shorena]

My friend suggested that once I've deleted my wallet to use the drive wiper feature in cc cleaner and set it to 3 passes, that should do it, do you agree?

Yep, I agree. CC cleaner also is a good tool.

[mlipscombmtl]

My friend suggested that once I've deleted my wallet to use the drive wiper feature in cc cleaner and set it to 3 passes, that should do it, do you agree?

Yep, I agree. CC cleaner also is a good tool.

ummmm...ok, so I'd have to load it up on another computer, confirm that my bitcoins are there, then destroy the .dat file on my computer (whilre preserving the one on my usb key obviously.) Is there another way to confirm it's not corrupt? I'd rather not have to load it onto another computer...

[shorena]

My friend suggested that once I've deleted my wallet to use the drive wiper feature in cc cleaner and set it to 3 passes, that should do it, do you agree?

Yep, I agree. CC cleaner also is a good tool.

ummmm...ok, so I'd have to load it up on another computer, confirm that my bitcoins are there, then destroy the .dat file on my computer (whilre preserving the one on my usb key obviously.) Is there another way to confirm it's not corrupt? I'd rather not have to load it onto another computer...

Well if the backup is corrupt and you deleted the original .dat you indeed have lost your money.
Not sure if its possible to check without using a computer.

If you are looking for some sort of coldstorage maybe a paperwallet or a newly made offline wallet will suit your needs.

https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet provides a nice step by step howto.

[TenDrawBTC]

What happens if you backup your wallet.dat

Keep your wallet running on your computer. Earn a couple more BTC then copy over the original wallet.dat file?

[mlipscombmtl]

My friend suggested that once I've deleted my wallet to use the drive wiper feature in cc cleaner and set it to 3 passes, that should do it, do you agree?

Yep, I agree. CC cleaner also is a good tool.

ummmm...ok, so I'd have to load it up on another computer, confirm that my bitcoins are there, then destroy the .dat file on my computer (whilre preserving the one on my usb key obviously.) Is there another way to confirm it's not corrupt? I'd rather not have to load it onto another computer...

Well if the backup is corrupt and you deleted the original .dat you indeed have lost your money.
Not sure if its possible to check without using a computer.

If you are looking for some sort of coldstorage maybe a paperwallet or a newly made offline wallet will suit your needs.

https://en.bitcoin.it/wiki/How_to_set_up_a_secure_offline_savings_wallet provides a nice step by step howto.

If I just open up the .dat file in note pad and it opens it shouldn't be corrupt then right?

[shorena]

-snip-
If I just open up the .dat file in note pad and it opens it shouldn't be corrupt then right?

Well if notepad can open it the file itself can be opened, but for the btc client to make something usefull of the data they have to be unchanged.

E.g. you open the file in notepad, change something and safe it. Notepad can still open the file, but the bitoin client may no longer consider it a valid walet.dat.

What happens if you backup your wallet.dat

Keep your wallet running on your computer. Earn a couple more BTC then copy over the original wallet.dat file?

The way I understand the wallet it would just update to the "new" version. If it wouldnt you could backup the wallet, spend your btc, restore, repeat.