>>I dont know how to simulate a disk failure.. Couple of things you could do. chmod 000 is one. 1. umount -l 2. mount ro only 3. If machine has hot swappable disks, pull out a disk.
-Bharath ________________________________ From: ccxixicc <ccxix...@foxmail.com> To: hdfs-user <hdfs-user@hadoop.apache.org> Sent: Wednesday, May 25, 2011 1:07 AM Subject: Re: What if one of the directory(dfs.name.dir) rw error ? I'm using 0.20.2. I had some test. I dont know how to simulate a disk failure, just chmod 000 dir1, the namenode shutdown immediately. And NN will hang if the nfs server down. ------------------ Original ------------------ From: "Harsh J"<ha...@cloudera.com>; Date: Wed, May 25, 2011 03:49 PM To: "hdfs-user"<hdfs-user@hadoop.apache.org>; Subject: Re: What if one of the directory(dfs.name.dir) rw error ? Yes. But depending on the version you're using, you may have to manually restart the NN after fixing the mount points, to get the directories in action again. 2011/5/25 ccxixicc <ccxix...@foxmail.com>: > > Hi,all > I set dfs.name.dir to a comma-delimited list of directories, dir1 is in > /dev/sdb1 dir2 is in /dev/sdb2 and dir3 is nfs derectory. > What happens if /dev/sdb1 disk error, so dir1 cannot be read and write? > What happens if nfs server down, so dir3 cannot be read and write? > Will hadoop ignore the bad directory and use the good directory and continue > server? > Thanks. > -- Harsh J
