Bitcoin Forum

Hi all

I have installed Bitcoin core 11.2 a week ago. It worked fine till today, when I got the following error (it happens shortly after bitcoin core starts):
"Error reading from database, shutting down".

Restarting my PC didn't help

I a using Windows7

Please advise - How can I fix it?

Yours

Asaf

#1 make sure core is closed
#2 open "run" with: win + r
#3 enter: c:\Program Files\Bitcoin\bitcoin-qt.exe -reindex (modify path if needed)
#4 confirm with ok
#5 wait till its done
#6 report back when its done

Thanks Shorena

It says it is Re-indexing blocks on disk.
I am 4 years and 47 week behind! (it is progressing, it was 7 years 5 minutes ago)

What exactly it is doing?

Asaf

The blockchain files are corrupted and thus the client is rebuilding the database all over again. This process is exactly the same with what happens when you first synchronize the blockchain but it does not need to download those all over again.

It would take sometime.

Thanks. I am in the process of doing that.
It should end sometimes in next few hours.

One more question - I am backing my wallet.dat in a few places after every transaction in my bitcoin core wallet (I rarely use it)
In case my computer crashes and I install a new version of bitcoin core, I know I should copy my backup wallet back to the wallet directory.

I still don't understand one thing - in the newly installed bitcoin core - should I simply use my old pass phrase in order to send bitcoins?
Is this pass pharse  basically the one that is protecting my wallet? (I have chosen a very strong one...)

Asaf

The pass phrase you used to encrypt the wallet can't change unless you change it explicitly - so if you are restoring a backed up wallet then it will require the password that you had last used for that wallet.

Yes, as CIYAM said. You can think of it like the password is protecting the file. It actually is, but not the entire file. Some information are not protected, e.g. your addresses and the label you gave them (if any). This is so you dont have to enter the password every time you start. This is also means if you set a new password you need to update your backups or remember both the old and the new password.

Oh and nice you are using core and the password topic is up, make sure you make regular backups. The more you use the wallet the more addresses are used and new ones are created. The wallet keeps a stock of ~100 address and private keys hidden from you until you need them, so you should make backups roughly every 50 addresses used (or transactions created) to make sure you can recover fully.

Once you have sync'd, I'd copy the blockchain to a USB stick. Then I would run an anti-virus scan and a trojan hunter, then check your hard disk for physical errors. If you find any malware, I'm afraid you may have to re-download the blockchain, unless you can be absolutely certain that the malware hasn't got at it.

It's not possible for the blockchain to have any virus that would affect your computer in it. The closest I can think of is the programs that are ran frequently. There are possibly some hashes matching virus signatures on the blockchain however, but it won't do anything.

Hardware errors and improper shutdown can cause a database corruption however.

It could be a trojan installer that was hidden in a block, and it waits for a trigger elsewhere to activate it. They used to hide them in all sorts of places - the word executable was one that I remember. But that was several years ago, I suspect they are more sophisticated now.

http://www.coinfox.info/news/persons/1733-kaspersky-lab-researcher-creates-virus-that-can-spread-through-the-blockchain