How to configure Dynamic Multipathing (DMP) for use with Oracle Automatic Storage Management (ASM).

book

Article ID: 100021363

calendar_today

Updated On:

Resolution

It may be desirable to use the DMP feature of Veritas Volume Manager while running Oracle ASM. In order to access the necessary DMP devices, volumes must be created in a Volume Manager Disk Group. This involves the following steps:
# vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
disk_0       auto:none       -            -            online invalid
disk_1       auto:none       -            -            online invalid
sun35100_0   auto:none       -            -            online invalid
 
For this example, sun35100_0 will be used.
 
1. Initialize the disk for Volume Manager use:
# /etc/vx/bin/vxdisksetup -i sun35100_0
 
2. Check the status:
# vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
disk_0       auto:none       -            -            online invalid
disk_1       auto:none       -            -            online invalid
sun35100_0   auto:cdsdisk    -            -            online <<<< Status has changed to online
.
3. Create a disk group for the disk called "oradg":
# vxdg init oradg sun35100_0
 
4. Check that the disk group has been created:
# vxdisk list
DEVICE       TYPE            DISK         GROUP        STATUS
disk_0       auto:none       -            -            online invalid
disk_1       auto:none       -            -            online invalid
sun35100_0   auto:cdsdisk    sun35100_0   oradg        online   <<<< disk is now in group "oradg"
 
5. Determine how large the volume can be so that the entire disk can be used.
# vxassist -g oradg maxsize sun35100_0
Maximum volume size: 4399104 (2148Mb)
 
6. Create a volume called "data" that's 4399104 sectors in size:
# vxassist -g oradg make data 4399104
 
7. Check the status of the volume"
# vxprint -qhtg oradg
dg oradg        default      default  4000     1247491602.22.mtvav210-c9e
 
dm sun35100_0   sun35100_0   auto     65536    4400896  -
 
v  data         -            ENABLED  ACTIVE   4399104  SELECT    -        fsgen
pl data-01      data         ENABLED  ACTIVE   4399104  CONCAT    -        RW
sd sun35100_0-01 data-01     sun35100_0 0      4399104  0         sun35100_0 ENA
 
The volume "data" in disk group "oradg" can now be accessed through the following raw and block devices respectively:
/dev/vx/rdsk/oradg/data
and
/dev/vx/dsk/oradg/data
 
It may be necessary to change ownership, group or permissions on the volume. Traditional Unix commands chown, chgrp and chmod should not be used because they are not persistent after a reboot. Use the vxedit command instead.  Multiple parameters may be set in a single command for the same volume. To set the user to "oracle", group to "dba" and permissions to "660" for the volume "data" in the "oradg" disk group, the command would be:
# vxedit -g oradg set user=oracle group=dba mode=660 data
Powered by Wolken Software