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InfoScale™ 9.0 Dynamic Multi-Pathing Administrator's Guide - AIX

Last Published: 2025-04-14

Product(s): InfoScale & Storage Foundation (9.0)

Platform: AIX

Extending an LVM rootvg when dmp_native_support is off

When an LVM root volume group (rootvg) is enabled for DMP, you can extend the rootvg by adding a SAN disk. If the root support is enabled with the vxdmpadm native enable command, the system must be rebooted before DMP can manage the new devices added to the LVM rootvg. In this case, the only DMP devices available to LVM are the devices in the rootvg. Therefore, you must extend the rootvg over the OS device paths. After the reboot, DMP can service the I/O to the new devices that were added to the LVM rootvg.

To add a SAN disk to a DMP-enabled rootvg

If the disk is under VxVM control, remove the disk from VxVM before you continue.
```
# vxdisk rm emc0_00a7
```

Clear the physical volume Identifiers (PVIDs) of all the paths to the SAN disk. Perform this step for each of the paths.

# vxdmpadm getsubpaths dmpnodename=emc0_00a7
NAME     STATE[A]   PATH-TYPE[M] CTLR-NAME  ENCLR-TYPE  ENCLR-NAME  ATTRS
=========================================================================
hdisk32  ENABLED(A)   -          fscsi0     EMC         emc0        -
hdisk6   ENABLED(A)   -          fscsi0     EMC         emc0        -
hdisk88  ENABLED(A)   -          fscsi1     EMC         emc0        -
hdisk99  ENABLED(A)   -          fscsi1     EMC         emc0        -

For example:

# chdev -l hdisk32 -a pv=clear

Update the PVID on the remaining paths of the added SAN disk. Perform this step for each of the paths.
```
# chdev -l hdisk6 -a pv=yes
```
```
# chdev -l hdisk88 -a pv=yes
```
```
# chdev -l hdisk99 -a pv=yes
```
Add the SAN disk to the DMP-enabled rootvg.
```
# extendvg rootvg hdisk32
```
Reboot the system.
```
# reboot
```

Verify the DMP rootvg configuration.

# vxdmpadm native list
PATH                      DMPNODENAME              
==============================================
hdisk143                  emc0_0039             
hdisk142                  emc0_0039            
hdisk141                  emc0_0039             
hdisk127                  emc0_0039             
hdisk32                   emc0_00a7              
hdisk6                    emc0_00a7               
hdisk88                   emc0_00a7               
hdisk99                   emc0_00a7

Verify that the DMP device is added to the rootvg. For example:

# lsvg -p rootvg
rootvg:
PV_NAME     PV STATE   TOTAL PPs   FREE PPs   FREE DISTRIBUTION
hdisk143    active     73          0          00..00..00..00..00
hdisk88     active     15          15         03..03..03..03..03

# lspv | grep -w rootvg
hdisk143   00c398ed00008e79   rootvg   active
hdisk142   00c398ed00008e79   rootvg   active
hdisk141   00c398ed00008e79   rootvg   active
hdisk127   00c398ed00008e79   rootvg   active
hdisk32    00c398edf9fae077   rootvg   active
hdisk6     00c398edf9fae077   rootvg   active
hdisk88    00c398edf9fae077   rootvg   active
hdisk99    00c398edf9fae077   rootvg   active