i describe you what is problem im facing :
there are two machines rac1 and rac2 on virtualbox and 3rd machine is openfiler also on virtualbox.
iscsi targets are accesible on both rac1 and rac2.
partitions on rac1 are like this :
[root@rac1 ~]# fdisk -l
Disk /dev/sda: 107.3 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1275 10241406 83 Linux
/dev/sda2 1276 1797 4192965 82 Linux swap / Solaris
/dev/sda3 1798 13054 90421852+ 83 Linux
Disk /dev/sdb: 18.4 GB, 18488492032 bytes
64 heads, 32 sectors/track, 17632 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 17632 18055152 83 Linux
Disk /dev/sdd: 15.8 GB, 15871246336 bytes
64 heads, 32 sectors/track, 15136 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 15136 15499248 83 Linux
Disk /dev/sdc: 16.8 GB, 16810770432 bytes
64 heads, 32 sectors/track, 16032 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 16032 16416752 83 Linux
[root@rac1 ~]# mount
/dev/sda3 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs 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)
/dev/sdb1 on /u01/san1 type ext3 (rw,_netdev)
/dev/sdc1 on /u02/san2 type ext3 (rw,_netdev)
/dev/sdd1 on /u03/san3 type ext3 (rw,_netdev)
oracleasmfs on /dev/oracleasm type oracleasmfs (rw)
d_shared_folder on /media/sf_d_shared_folder type vboxsf (gid=160,rw)
**********************************************************************************************************
[root@rac2 ~]# fdisk -l
Disk /dev/sda: 107.3 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 1275 10241406 83 Linux
/dev/sda2 1276 1797 4192965 82 Linux swap / Solaris
/dev/sda3 1798 13054 90421852+ 83 Linux
Disk /dev/sdb: 15.8 GB, 15871246336 bytes
64 heads, 32 sectors/track, 15136 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 15136 15499248 83 Linux
Disk /dev/sdd: 18.4 GB, 18488492032 bytes
64 heads, 32 sectors/track, 17632 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 17632 18055152 83 Linux
Disk /dev/sdc: 16.8 GB, 16810770432 bytes
64 heads, 32 sectors/track, 16032 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 16032 16416752 83 Linux
[root@rac2 ~]# mount
/dev/sda3 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs 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)
/dev/sdb1 on /u01/san1 type ext3 (rw,_netdev)
/dev/sdc1 on /u02/san2 type ext3 (rw,_netdev)
/dev/sdd1 on /u03/san3 type ext3 (rw,_netdev)
d_shared_folder on /media/sf_d_shared_folder type vboxsf (gid=160,rw)
*****************************************************************************************************
when i execute command
[root@rac1 ~]# /usr/sbin/oracleasm createdisk DISK1 /dev/sdb1
Unable to open device "/dev/sdb1": Device or resource busy