Each datanode has a web page at http://datanode:50075/blockScannerReport where you can see details about the scans.
Tom On Thu, Jan 29, 2009 at 7:29 AM, Raghu Angadi <rang...@yahoo-inc.com> wrote: > Owen O'Malley wrote: >> >> On Jan 28, 2009, at 6:16 PM, Sriram Rao wrote: >> >>> By "scrub" I mean, have a tool that reads every block on a given data >>> node. That way, I'd be able to find corrupted blocks proactively >>> rather than having an app read the file and find it. >> >> The datanode already has a thread that checks the blocks periodically for >> exactly that purpose. > > since Hadoop 0.16.0. scans all the blocks every 3 weeks (by default, > interval can be changed). > > Raghu. >
