问题
According to the wiki
http://forge.fiware.org/plugins/mediawiki/wiki/fiware/index.php/BigData_Analysis_-_Quick_Start_for_Programmers#Step_1._Create_a_Cosmos_account
and via
ssh my_user@cosmos.lab.fi-ware.org
1) I realize that there is no folder '/user/my_user' but '/home/my_user'. Why? May I suposse that my user is not propertly created?
2) I am trying to create a folder, but I get the SafeModeException:
hadoop fs -mkdir /home/my_user/test
mkdir: org.apache.hadoop.hdfs.server.namenode.SafeModeException: Cannot create directory /home/my_user/test. Name node is in safe mode.
I have tried:
hadoop dfsadmin -safemode leave
with this result:
safemode: org.apache.hadoop.security.AccessControlException: Access denied for user my_user. Superuser privilege is required
Thanks!
回答1:
Pablo, yesterday the Namenode of the Cosmos instance entered in safe mode due to the HDD was running out of space. It should be fixed now, but while the safe mode was enabled, nothing could be done with HDFS, including your user account creation.
I have completed the registration process manually, try it and let me know if something is still wrong (I also answered you by private email, with all the details regarding your user).
Regarding the Hadoop commands you tried (leaving safe mode and creating a folder under /user), these are privileged operations :)
来源：https://stackoverflow.com/questions/28302418/safemodeexception-at-cosmos-lab-fi-ware-org