ASM and install Oracle Grid Infrastructure on Oracle Linux 5.7

Hi DBAs,

I am trying to install Oracle Grid Infrastructure on Oracle Linux 5.7 and I got the following
error :
INFO: Read: Configuring ASM failed with the following message:
INFO: Read: One or more diskgroup(s) creation failed as below:
INFO: Read: DiskGroup DATAJZ creation failed with the following message:
INFO: Read: ORA-15018: diskgroup cannot be created
INFO: Read: ORA-15020: discovered duplicate ASM disk "DATAJZ_0009"
INFO: Read: ORA-15080: synchronous I/O operation to a disk failed

I have deleted disks one by one and I got the same error

INFO: Read: Configuring ASM failed with the following message:
INFO: Read: One or more diskgroup(s) creation failed as below:
INFO: Read: DiskGroup DATAJZ creation failed with the following message:
INFO: Read: ORA-15018: diskgroup cannot be created
INFO: Read: ORA-15020: discovered duplicate ASM disk "DATAJZ_0007"
INFO: Read: ORA-15080: synchronous I/O operation to a disk failed

these are the steps :

dd if=/dev/zero of=/u01/asmdisks/_file_disk_01 bs=1k count=2359296
... to
dd if=/dev/zero of=/u01/asmdisks/_file_disk_10 bs=1k count=2359296
----
losetup /dev/loop1 /u01/asmdisks/_file_disk_01
... to
losetup /dev/loop10 /u01/asmdisks/_file_disk_10

----
ln -s /dev/loop1 /dev/_xvdb01
... to
ln -s /dev/loop10 /dev/_xvdk10

---

/usr/sbin/oracleasm createdisk ASMDISK01 /dev/_xvdb01
...
/usr/sbin/oracleasm createdisk ASMDISK10 /dev/_xvdk10

-----

oracleasm scandisks
oracleasm listdisks

Thanks in advance for your help