Document Type | Technical Information
Categoty | Administration
Applicable Product Versions | T7, T6
Document Number | TADTI130
Overview
What is Multipath?
- This is a situation where multiple controllers are physically assigned to the same disk. (There are two PATHs to the same disk.)
- In other words, there are multiple paths but they all access the same disk.
- Since there are two PATHs, the OS recognizes them as two devices, but although two are shown, they are actually the same device.
- A multipath solution is what combines these two devices into one.
- There are hardware-based and logical (iSCSI) configuration methods.
- In short, to build Multipath, you need to create multiple access PATHs to the same disk.
Method
Example of ISCSI MULTIPATH Configuration
You can configure multipath using software rather than hardware equipment.
There are several methods, but disks provided via ISCSI can be used for multipath.
- ISCSI target: Provides disk
- ISCSI Initiator: Uses disk
Example configuration for using /dev/sdb and /dev/sdc of the ISCSI target as multipath
ISCSI TARGET Configuration
- This is a configuration where /dev/sdb of the ISCSI target server is provided as iscsi_disk01 (lun0).
- This is a configuration where /dev/sdc of the ISCSI target server is provided as iscsi_disk02 (lun1).
- Portals are designated so that iscsi_disk01 and iscsi_disk02 can be used via 10.0.10.3:3260 and 10.0.10.5:3260.
ISCSI Initiator
- This is iscsi_disk01 (lun0) (uuid: 36001405f455cae7657d4377812f36455) received from the ISCSI target.
- Allocated as sdb and sdc on the ISCSI Initiator.
- sdb [iscsi_disk01(lun0)], sdc [iscsi_disk01(lun0)] are grouped as a multipath named mpatha.
- This is iscsi_disk02 (lun1) (uuid: 3600140541a58a71120e4102a678cb7ae) received from the ISCSI target.
- Allocated as sdc and sde on the ISCSI Initiator.
- sdb [iscsi_disk02(lun1)], sdc [iscsi_disk02(lun1)] are grouped as a multipath named mpathb.
Reference Document