InfoScale™ 9.0 Dynamic Multi-Pathing Administrator's Guide - Solaris
- Understanding DMP
- How DMP works
- Disk device naming in DMP
- Setting up DMP to manage native devices
- Using Dynamic Multi-Pathing (DMP) devices with Oracle Automatic Storage Management (ASM)
- Administering DMP
- Managing DMP devices for the ZFS root pool
- Administering DMP using the vxdmpadm utility
- Gathering and displaying I/O statistics
- Specifying the I/O policy
- Administering disks
- Discovering and configuring newly added disk devices
- About discovering disks and dynamically adding disk arrays
- How to administer the Device Discovery Layer
- Changing the disk device naming scheme
- Dynamic Reconfiguration of devices
- About the DMPDR utility
- Reconfiguring a LUN online that is under DMP control using the Dynamic Reconfiguration tool
- Manually reconfiguring a LUN online that is under DMP control
- Event monitoring
- Performance monitoring and tuning
- Appendix A. DMP troubleshooting
- Appendix B. Reference
About operating system-based naming
In the OS-based naming scheme, all disk devices are named using the c#t#d#s# format.
The syntax of a device name is c#t#d#s#, where c# represents a controller on a host bus adapter, t# is the target controller ID, d# identifies a disk on the target controller, and s# represents a partition (or slice) on the disk.
Note:
DMP assigns the name of the DMP meta-device (disk access name) from the multiple paths to the disk. DMP sorts the names by controller, and selects the smallest controller number. For example, c1 rather than c2. If multiple paths are seen from the same controller, then DMP uses the path with the smallest target name. This behavior make it easier to correlate devices with the underlying storage.
If a CVM cluster is symmetric, each node in the cluster accesses the same set of disks. This naming scheme makes the naming consistent across nodes in a symmetric cluster.
The boot disk (which contains the root file system and is used when booting the system) is often identified to VxVM by the device name c0t0d0.
By default, OS-based names are not persistent, and are regenerated if the system configuration changes the device name as recognized by the operating system. If you do not want the OS-based names to change after reboot, set the persistence attribute for the naming scheme.
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