Multipath configuration on RHEL6

1. Check if you have already installed device-mapper-multipath rpm, if not then install it.

rpm -qa device-mapper-multipath

2. If /etc/multipath.conf file doesn’t exist, then copy it from /usr/share/doc/device-mapper-multipath-*

cp /usr/share/doc/device-mapper-multipath-0.4.9/multipath.conf /etc/multipath.conf

3. Find WWIDs that should be added to multipath configuration.

# scsi_id -g -u /dev/sdb

4. Edit the /etc/multipath.conf configuration file

defaults {
        user_friendly_names yes
        path_grouping_policy    failover

blacklist {
        wwid "*"

blacklist_exceptions {
        wwid "36001438009b044d90000900000780000"

multipaths {
        multipath {
                wwid                    "36001438009b044d90000900000780000"
                alias                   asm1

5.  Add module to the Linux kernel:

modprobe dm-multipath

6. Start multipath service:

service multipathd start

7. If you have any syntax errors or any parameters that do not work in your Linux version, the following command will show:

multipath -d

8. Commit the configuration:

multipath -v2

9. The following command must find the paths , or you have a bad configuration in multipath.conf file:

multipath -ll

10. Make devices configured after a reboot:

chkconfig multipathd on

If you have made any mistakes in multipath.conf file then correct them and do  the following steps to make changes take affect :

1. edit the /etc/multipath.conf

2.  Reload the multipath service:

service multipathd reload

3.  Remove all unused multipath devices

multipath -F

4.  Check again that syntax is correct:

multipath –d

5.  Commit the changes:

multipath –v2

Note that, this configuration is very simple, but it is working also perfectly.

For more multipath options and more sophisticated configuration, see the following documentation.

Installation problem of OEL6 on HP ProLiant DL360e Gen8 with HP Dynamic Smart Array B320i Controller

This post is dedicated to the Oracle Enterprise Linux 6.x installation on HP server with Dynamic Smart Array B320i Controller.

Brief description of the problem:

During OEL6 installation on HP server installer was not able to see local disks, on which system should be installed. Local disk specification was the following: Two 300GB disks involved into the RAID 1 and controller for RAID was Dynamic Smart Array B320i.

Installer was able to see multipath devices and any other external devices, like flash drive, but not local disks.

On HP site, there is written that the minimum supported Oracle Linux updates for HP  DL380e series are the following:

DL380e Gen8

  • Oracle Linux/UEK 6.2
  • Oracle Linux/UEK 5.8

Minimum support includes all future updates of the indicated release unless a maximum is listed. (Example: Oracle 6 implies support for Oracle 6.x, unless it’s specifically called out in the notes as "not supported with 6.x")”

And HP also declaims that it gives its drivers to the supported OSs manufacturers.

To tell the truth, I’ve tried Oracle Enterprise Linux 5.5, 6.0, 6.2 and 6.4 versions, but none of them was able to see the local storage.

After a lot of troubleshooting, I found the solution.


The solution implies the HP Dynamic Smart Array SATA RAID Controller Driver for Red Hat Enterprise Linux 6 installation before OS installation.

1. Download drivers from the following link, click here.

Note: hpvsa-1.2.4-4.rhel6u1.x86_64.dd.gz is for RHEL6.1
hpvsa-1.2.4-4.rhel6u2.x86_64.dd.gz is for RHEL6.2
hpvsa-1.2.4-4.rhel6u3.x86_64.dd.gz is for RHEL6.3

Because of we are installing Oracle Enterprise Linux 6.2 which is based on RHEL6.2, we need hpvsa-1.2.4-4.rhel6u2.x86_64.dd.gz.

2. Extract gz file, you should have file with the extension of dd. Write this file to the flash drive and connect it to the server.

3. Put Oracle Enterprise Linux 6.2 installation disk and when the following window appears, press the TAB.


At the end of the command write install dd(separated from the previous command with space) and press Enter.

4. Choose the driver file, that we mentioned earlier and continue the installation.

Oracle EL should now see the local disk without any problem. Good Luck.