# modprobe dm-multipath – add multipathing module to Linux kernel
# modprobe dm-round-robin – add multipathing round-robin module to Linux kernel
# /etc/init.d/multipathd start – start multipath service
# multipath – automatically detect multiple paths to devices and configure multipathing
# chkconfig multipathd on – turn on multipath service
# multipath –l – displays all paths to devices
The /dev/mapper/mpathN devices are persistent and they are created early in the boot process. Therefore these are the device names that should be used to access the multipathed devices.
For example:
- /usr2/sybase/ASE1503/dev/wdb_data – is a symbolic link pointing to /dev/raw/raw73
- /dev/raw/raw73 – is a raw character device mapped to /dev/mapper/mp_wdb_data
- /dev/mapper/mp_wdb_data – is a multipath device which contains two paths /dev/sdbf & /dev/sds.
- /dev/sdbf – is block device that corresponds to SCSI generic raw character device /dev/sg61
- /dev/sds – is block device that corresponds to SCSI generic raw character device /dev/sg20