HI Suresh, Thank you for your suggestions, all of the nodes (10) were registered when I brought the cluster back up.
My one thought was that due to an IT error one of the 12 partitions used for data on each datanode was undersized and had potentially filled up, but I don't see how it would have then caused that much data loss - I would have expected at most 1/12 of the data to go missing - not over 40%. thank you, -chris On Feb 19, 2011, at 12:10 AM, suresh srinivas wrote: > The problem is that replicas for 3609 blocks are not reported to namenode. > > Do you have datanodes in exclude file? What is the number of registered nodes > before start compared to what it is now? Removing all the datanodes from > exclude file (if there are any) and restarting the cluster should fix the > issue. > > On Fri, Feb 18, 2011 at 5:43 PM, Chris Tarnas <c...@email.com> wrote: > I've hit a data curroption problem in a system we were rapidly loading up, > and I could really use some pointers on where to look for the root of the > problem as well as any possible solutions. I'm running the cdh3b3 build of > Hadoop 0.20.2. I experienced some issues with a client (Hbase regionserver) > getting an IOException talking with the namenode. I thought the namenode > might have been resourced starved (maybe not enough RAM). I first ran a fsck > and the filesystem was healthy and then shutdown hadoop (stop-all.sh) to > update the hadoop-env.sh to allocate more memory to the namenode, then > started up hadoop again (start-all.sh). > > After starting up the server I ran another fsck and now the filesystem is > corrupt and about 1/3 or less of the size it should be. All of the datanodes > are online, but it is as if they are all incomplete. > > I've tried using the previous checkpoint from the secondary namenode to no > avail. This is the fsck summary > > blocks of total size 442716 B.Status: CORRUPT > Total size: 416302602463 B > Total dirs: 7571 > Total files: 7525 > Total blocks (validated): 8516 (avg. block size 48884758 B) > ******************************** > CORRUPT FILES: 3343 > MISSING BLOCKS: 3609 > MISSING SIZE: 169401218659 B > CORRUPT BLOCKS: 3609 > ******************************** > Minimally replicated blocks: 4907 (57.62095 %) > Over-replicated blocks: 0 (0.0 %) > Under-replicated blocks: 4740 (55.659935 %) > Mis-replicated blocks: 0 (0.0 %) > Default replication factor: 3 > Average block replication: 0.7557539 > Corrupt blocks: 3609 > Missing replicas: 8299 (128.94655 %) > Number of data-nodes: 10 > Number of racks: 1 > > The namenode had quite a few WARNS like this one (The list of excluded nodes > is all of the nodes in the system!) > > 2011-02-18 17:06:40,506 WARN > org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Not able to place enough > replicas, still in need of 1(excluded: 10.56.24.15:50010, 10.56.24.19:50010, > 10.56.24.16:50010, 10.56.24.20:50010, 10.56.24.14:50010, 10.56.24.17:50010, > 10.56.24.13:50010, 10.56.24.18:50010, 10.56.24.11:50010, 10.56.24.12:50010) > > > > I grepped for errors and warns on all 10 of the datanode logs and only found > that over the last day two nodes had a total of 8 warns and 1 error: > > node 5: > > 2011-02-18 03:44:56,642 WARN > org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: First Verification > failed for blk_-8223286903671115311_101182. Exception : java.io.IOException: > Input/output error > 2011-02-18 03:45:04,440 WARN > org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: Second Verification > failed for blk_-8223286903671115311_101182. Exception : java.io.IOException: > Input/output error > 2011-02-18 06:53:17,081 WARN > org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: First Verification > failed for blk_8689822798201808529_99687. Exception : java.io.IOException: > Input/output error > 2011-02-18 06:53:25,105 WARN > org.apache.hadoop.hdfs.server.datanode.DataBlockScanner: Second Verification > failed for blk_8689822798201808529_99687. Exception : java.io.IOException: > Input/output error > 2011-02-18 12:09:09,613 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: > Could not read or failed to veirfy checksum for data at offset 25624576 for > block blk_-8776727553170755183_302602 got : java.io.IOException: Input/output > error > 2011-02-18 12:17:03,874 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: > Could not read or failed to veirfy checksum for data at offset 2555904 for > block blk_-1372864350494009223_328898 got : java.io.IOException: Input/output > error > 2011-02-18 13:15:40,637 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: > Could not read or failed to veirfy checksum for data at offset 458752 for > block blk_5554094539319851344_322246 got : java.io.IOException: Input/output > error > 2011-02-18 13:12:13,587 ERROR > org.apache.hadoop.hdfs.server.datanode.DataNode: > DatanodeRegistration(10.56.24.15:50010, > storageID=DS-1424058120-10.56.24.15-50010-1297226452840, infoPort=50075, > ipcPort=50020):DataXceiver > > Node 9: > > 2011-02-18 12:02:58,879 WARN org.apache.hadoop.hdfs.server.datanode.DataNode: > Could not read or failed to veirfy checksum for data at offset 16711680 for > block blk_-5196887735268731000_300861 got : java.io.IOException: Input/output > error > > Many thanks for any help or where I should look. > -chris > > > > > > -- > Regards, > Suresh >
