Configuration: Device Mapper Multipath for Linux 221
Device Mapper Configuration Steps
To complete the DM multipathing configuration and make the storage
available to the Linux host server:
1
Scan for virtual disks. See "Scan for Newly Added Virtual Disks" on
page 221.
2
Display the multipath device topology. See "Display the Multipath Device
Topology Using the Multipath Command" on page222.
3
Create a partition on a multipath device node. See "Create a New fdisk
Partition on a Multipath Device Node" on page223.
4
Add a partition to DM. See "Add a New Partition to Device Mapper" on
page 223.
5
Create a file system on a DM partition. See "Create a File System on a
Device Mapper Partition" on page224.
6
Mount a DM partition. See "Mount a Device Mapper Partition" on
page 224.
NOTE: In the following command descriptions <x> is used to indicate where a
substitution must be made. On RHEL systems <x> is the number assigned to the
device. On SLES systems <x> is the letter(s) assigned to the device.
Scan for Newly Added Virtual Disks
The rescan_dm_devs command scans the host server system looking for
existing and newly added virtual disks mapped to the host server.
# rescan_dm_devs
If an array virtual disk (VD) is mapped to the host server at a later time, the
rescan_dm_devices command must be run again to make the VD a
visible LUN to the operating system.
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