This procedure describes removing devices from Linux Device Mapper Multipath control and enabling DMP on the devices.
Plan for system downtime for the following procedure.
The migration steps involve system downtime on a host due to the following:
Need to stop applications
Need to stop the VCS services if using VCS
The procedure involves one or more host reboots
To remove devices from Device Mapper Multipath control and enable DMP
# lvchange -a n lvname
/etc/multipath.conf
file to blacklist all device mapper devices. This step disables multi-pathing for all devices.# Blacklist all devices by default. blacklist { devnode "*" }
/dev/dm-*
and /dev/mpath/*
device entries. For RHEL 7, SLES 12, and supported RHEL distributions:
# systemctl restart multipathd
For earlier versions of RHEL, SLES and supported RHEL distributions:
# service multipathd restart
For RHEL 7, SLES 12, and supported RHEL distributions:
# systemctl stop multipathd
For earlier versions of RHEL, SLES and supported RHEL distributions:
# service multipathd stop
For RHEL 7, SLES 12, and supported RHEL distributions:
# systemctl disable multipathd
For earlier versions of RHEL, SLES and supported RHEL distributions:
# chkconfig multipathd off
# vxdmpadm settune dmp_native_support=on
The above command also enables DMP support for LVM root.
This step can take some time depending upon the number of LVs.