Dell PowerVault MD3200 Owner's Manual - Page 169

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 169. 2 Display the multipath device topology. See "Display the Multipath Device Topology Using the Multipath Command" on page 169. 3 Create a partition on a multipath device node. See "Create a New fdisk Partition on a Multipath Device Node" on page 171. 4 Add a partition to DM. See "Add a New Partition to Device Mapper" on page 171. 5 Create a file system on a DM partition. See "Create a File System on a Device Mapper Partition" on page 172. 6 Mount a DM partition. See "Mount a Device Mapper Partition" on page 172. The following instructions show how to complete each of these steps. In the following command descriptions is used to indicate where a substitution should be made. On RHEL systems is the number assigned to the device. On SLES systems 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. Display the Multipath Device Topology Using the Multipath Command The multipath command adds newly scanned and mapped virtual disks to the Device Mapper tables and creates entries for them in the /dev/mapper directory on the host server. These devices are the same as any other block devices in the host. To list all the multipath devices run the following command. Configuration: Device Mapper Multipath for Linux 169