【发布时间】：2014-05-15 03:19:03
【问题描述】：
我通过sqoop命令成功从mysql上传数据到HDFS。
MySQL Hadoop 集群有
Namename 的 1 个节点 1 个用于辅助 NameNode 的节点 Jobtracker 的 1 个节点 Datanade + Tasktracker 的 3 个节点
之后我停止了 hadoop 集群。
再次启动 Hadoop
在命令下方使用
namenode -format (start NameNode)
place new VERSION number in all datanode VERSION FILE
now START DATANODE
在启动 datanode 时，我在 HDFS 中上传的 MYSQL 数据似乎丢失了。
以下是数据节点日志的输出。
2014-05-15 07:46:56,018 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_2445513848423894029_1337 at file /app/hadoop/data/dn/current/blk_2445513848423894029
2014-05-15 07:46:56,018 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_3541234094053021888_1338 at file /app/hadoop/data/dn/current/blk_3541234094053021888
2014-05-15 07:46:56,018 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_3862391472172526583_1347 at file /app/hadoop/data/dn/current/blk_3862391472172526583
2014-05-15 07:46:56,018 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_4001223662527683746_1387 at file /app/hadoop/data/dn/current/blk_4001223662527683746
2014-05-15 07:46:56,018 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_4143551839757190038_1410 at file /app/hadoop/data/dn/current/subdir14/blk_4143551839757190038
2014-05-15 07:46:56,019 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_5292612097544035620_1384 at file /app/hadoop/data/dn/current/blk_5292612097544035620
2014-05-15 07:46:56,019 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_5318982235915332439_1333 at file /app/hadoop/data/dn/current/blk_5318982235915332439
2014-05-15 07:46:56,019 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_5806860765395122737_1388 at file /app/hadoop/data/dn/current/blk_5806860765395122737
2014-05-15 07:46:56,019 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_6490571696460682483_1302 at file /app/hadoop/data/dn/current/blk_6490571696460682483
2014-05-15 07:46:56,020 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_7721528058087862562_1336 at file /app/hadoop/data/dn/current/blk_7721528058087862562
2014-05-15 07:46:56,020 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_7734832800955956873_1375 at file /app/hadoop/data/dn/current/blk_7734832800955956873
2014-05-15 07:46:56,020 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_8691928504867292802_1297 at file /app/hadoop/data/dn/current/blk_8691928504867292802
2014-05-15 07:46:56,020 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_8861743153245195509_1303 at file /app/hadoop/data/dn/current/blk_8861743153245195509
2014-05-15 07:46:56,021 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_8921828525927242630_1300 at file /app/hadoop/data/dn/current/blk_8921828525927242630
2014-05-15 07:46:56,021 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: Deleted blk_8938258584084219299_1344 at file
【问题讨论】：
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请陈述一个具体问题，以便用户确切知道您需要什么帮助。
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你想要什么......请添加更多关于你的错误的信息
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第三步到底是什么？ “在所有数据节点版本文件中放置新版本号”？
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当我将 namenode 的新 VERSION 更改为所有 datanode 时。并启动datanodes，所有上传的数据都被删除并出现以下错误已删除文件/app/hadoop/data/dn/current/blk_6490571696460682483中的blk_6490571696460682483_1302我的问题是当我们使用Haddop fs -format命令时所有数据都已格式化，有没有办法恢复数据
标签： hadoop