Infrastructure Software

We have an RHEL4 10g system using ASM, following the initial installation the ASM and DB instances came up ok. Since rebooting the server one of the diskgroups will not mount. Manually trying to mount the diskgroup produces the following:

SQL> alter diskgroup RECOVERY mount;
alter diskgroup RECOVERY mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15040: diskgroup is incomplete
ORA-15042: ASM disk "2" is missing

Note: Disk "2" in the RECOVERY DG is named DISK9 and is associated with /dev/cciss/c1d0p1

The storage system (HP MSA500 G2) and the OS both confirm there are no problems with the disk. It appears as if ASM is not finding all the disks:

# /etc/init.d/oracleasm listdisks
DISK1
DISK2
DISK3
DISK4
DISK5
DISK6
DISK7
DISK8

But querying the disks shows that the missing disk is there and marked as ASM

# /etc/init.d/oracleasm querydisk /dev/cciss/c1d*p1
Disk "/dev/cciss/c1d0p1" is marked an ASM disk with the label "DISK9"
Disk "/dev/cciss/c1d1p1" is marked an ASM disk with the label "DISK1"
Disk "/dev/cciss/c1d2p1" is marked an ASM disk with the label "DISK2"
Disk "/dev/cciss/c1d3p1" is marked an ASM disk with the label "DISK3"
Disk "/dev/cciss/c1d4p1" is marked an ASM disk with the label "DISK4"
Disk "/dev/cciss/c1d5p1" is marked an ASM disk with the label "DISK5"
Disk "/dev/cciss/c1d6p1" is marked an ASM disk with the label "DISK6"
Disk "/dev/cciss/c1d7p1" is marked an ASM disk with the label "DISK7"
Disk "/dev/cciss/c1d8p1" is marked an ASM disk with the label "DISK8"

Any ideas?

Thanks