Dell PowerVault MD3820f - Manual (Page 198)

Create A New fdisk Partition On A Multipath Device Node
The fdisk command allows creation of partition space for a file system on the newly scanned and
mapped virtual disks that have been presented to Device Mapper.
To create a partition with the multipathing device nodes /dev/mapper/mpath<x>, for example, use the
following command:
# fdisk /dev/mapper/mpath<x>
where mpath<x> is the multipathing device node on which you want to create the partition.
NOTE: The <x> value is an alphanumeric operating system dependent format. The corresponding
value for mapped virtual disks can be seen using the previously run multipath command. See your
operating system documentation for additional information on fdisk.
Add A New Partition To Device Mapper
The kpartx command adds the new fdisk partition to the Device Mapper list of usable partitions. See
examples below, where mpath<x> is the device node on which the partition was created.
# kpartx –a /dev/mapper/mpath<x>
If successful, the command does not display an output. To verify success and view exact partition
naming, you can use these commands to see the full partition names assigned.
# cd /dev/mapper# ls
The following are some examples of the general mapping formats:
• On Red Hat Enterprise Linux (RHEL) hosts, a partition node has the format:/dev/mapper/
mpath<x>p<y>
Where <x> is the alphabetic number for the multipathing device, <y> is the partition number for this
device.
• On SUSE Linux Enterprise Server (SLES) 11.x hosts, a partition node has the format:/dev/mapper/
mpath<x>-part<y>
Where <x> is letter(s) assigned to the multipathing device and <y> is the partition number.
• On SLES 10.3 hosts, a partition node has the format: /dev/mapper/mpath<x>_part<y>
Where <x> is the letter(s) assigned to the multipathing device and <y> is the partition number.
NOTE: After creating a partition on a device capable of multipathing, all I/O operations, including
file system creation, raw I/O and file system I/O, must be done through the partition node, and not
through the multipathing device nodes.
Create A File System On A Device Mapper Partition
Use the standard mkfs command to create the file system on the newly created Device Mapper partition.
For example:
# mkfs –t <filesystem type> /dev/mapper/<partition node>
where <partition node> is the partition on which the file system is created.
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