oracle rac 时，ocfs2 仲裁磁盘无法加载

oracle rac 时，有第二个节点的，ocfs2 仲裁磁盘无法加载 
 在第一个节点上，该仲裁磁盘可以正常的加载

[root@guolinuxorcl1 ocfs2]#  mount -t ocfs2 -o datavolume,nointr /dev/sdb1 /u02/oradata/orcl
[root@guolinuxorcl1 ocfs2]# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/sda1 on /boot type ext3 (rw)
none on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
configfs on /config type configfs (rw)
ocfs2_dlmfs on /dlm type ocfs2_dlmfs (rw)
/dev/sdb1 on /u02/oradata/orcl type ocfs2 (rw,_netdev,datavolume,nointr,heartbeat=local)

但是在第二个节点上却无法加载

[root@guolinuxorcl2 ~]# mounted.ocfs2 -d
Device                FS     UUID                                  Label
/dev/sdb1             ocfs2  004883a4-f8b7-41be-b8b3-7954d02bfc64  oracrsfiles
[root@guolinuxorcl2 ~]# mounted.ocfs2 -f
Device                FS     Nodes
/dev/sdb1             ocfs2  Unknown: Bad magic number in inode  

每次加载都报错

ocfs2_hb_ctl: Bad magic number in inode while reading uuid mount.ocfs2: Error when attempting to run /sbin/ocfs2_hb_ctl: "Operation not permitted"

解决办法如下

1、先重已加载的节点卸载掉该硬盘。

2、在无法加载的节点格式化该盘。

 记住用dd格式化，而不是fdisk，如果只是用fdisk删除分区和格式化，第二个节点上始终记录这个盘处于 bad magic状态

可以看到dd以后，sdb1 在ocfs2 的状态立刻改变了，但如果是只是fdisk 掉 sdb1,状态是不会变的，先dd，然后用fdisk重新分区。

[root@guolinuxorcl2 ~]# dd if=/dev/zero of=/dev/sdb1 bs=8192 count=2560
2560+0 records in
2560+0 records out
[root@guolinuxorcl2 ~]# mounted.ocfs2 -d
Device                FS     UUID                                  Label
[root@guolinuxorcl2 ~]# fdisk /dev/sdb

Command (m for help): d
Selected partition 1

Command (m for help): 1
1: unknown command
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): d
No partition is defined yet!

Command (m for help): w    
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table.
The new table will be used at the next reboot.
Syncing disks.

3、在节点二上对该硬盘mount。

4、在节点一上对该硬盘mount。

总结：如果仲裁盘是新安装的系统，可以用该方法试着解决该错误。把仲裁盘dd格式化，然后重新加载。