Bitcoin Forum

I have a full node and it crashed due to an apparent disk read error.

"ERROR: ReadBlockFromDisk: Deserialize or I/O error - CAutoFile::read: fread failed" etc.

What is the proper way to recover from such an error and get the node running again?

I don't know the optimum method for Bitcoin, but a couple of methods occur to me, and I'd be grateful for opinions. I'm assuming it's a blockchain record.

I'd copy to entire blockchain onto and SDcard or SSD disk, and omit the error file (I use file to refer to a single record containing multiple blocks). You should be able to obtain a copy, and add that to the Blockchain directory. I assume that the blockchain verification will accept this. What would happen if you didn't add the deleted record? Would resynchronisation notice that it was missing, and recover it from an active node to rebuild the chain?

I know one tool that can help you to recover files. I had the similar situation with my Mac, I used Disk Drill for Mac (http://download.cnet.com/Disk-Drill/3000-2094_4-75984417.html). This app knows how to recover lost files on Mac OS  and supports most major file types and file systems. It can recover your files from practically any storage device. If it worked for me then it should help you too.

if i remeber well, fread() function it is used to read block size and block content from blockchain.
maibe do you have HDD with corrupted sectors???
if you have Windows you can use one of this free software...
https://www.geckoandfly.com/21498/check-repair-hard-disk-bad-sector/
or simply do a chkdsk from dos shell

try to insert that disk to other pc and run scandisk to fix it!
may be it can help.

if you are using Windows, open dos shell, and type "chkdsk /F"
the "/F" parameter still for FIX.
it can repair bad Sector.

just give it a try...