Adding DMP devices to an existing LVM volume group or creating a new LVM volume group


Adding DMP devices to an existing LVM volume group or creating a new LVM volume group
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When the dmp_native_support is ON, you can create a new LVM volume group on an available DMP device. You can also add an available DMP device to an existing LVM volume group. After the LVM volume groups are on DMP devices, you can use any of the LVM commands to manage the volume groups.

To create a new LVM volume group on a DMP device or add a DMP device to an existing LVM volume group

Choose disks that are available for use by LVM.
Use the vxdisk list command to identify these types of disks.
- Disks that are not in use by VxVM
  
  The output of vxdisk list shows these disks with the Type auto:none and the Status as online invalid.
The example shows available disks.
```
# vxdisk list
```
```
DEVICE            TYPE       DISK    GROUP    STATUS
. . .
emc_clariion0_84  auto:none  -       -        online invalid
emc_clariion0_85  auto:none  -       -        online invalid
```

Identify the ODM device name that corresponds to the device. The ODM device name is a truncated form of the DMP device name, since the ODM database requires a shorter name. The dmpname is an attribute of the ODM device name.

In this example, the DMP device name is emc_clariion0_84, and the ODM device name is emc_clari0_84. The enclosure index and the array volume ID (AVID) in the enclosure based name (EBN) are retained from the DMP device name.

# lspv | grep emc_clari0
emc_clari0_84       none                      None
emc_clari0_85       none                      None
# lsdev -Cc disk
. . .
emc_clari0_84     Available          Veritas DMP Device
emc_clari0_85     Available          Veritas DMP Device
# lsattr -El emc_clari0_84
dmpname   emc_clariion0_84  DMP Device name            True
pvid      none				          Physical volume identifier True
unique_id DGC%5FRAID%200%5FCK200080300687%5F600601601C101F0
0E5CF099D7209DE11 Unique device identifier   True

Create a new LVM volume group on a DMP device.

Use the ODM device name to specify the DMP device.

# mkvg -y newvg emc_clari0_84
0516-1254 mkvg: Changing the PVID in the ODM.
newvg

# lspv
emc_clari0_84       00c95c90837d5ff8      newvg	active
emc_clari0_85       none                  None

Add a DMP device to an existing LVM volume group.

Use the ODM device name to specify the DMP device.

# extendvg -f newvg emc_clari0_85
0516-1254 mkvg: Changing the PVID in the ODM.

# lspv
emc_clari0_84       00c95c90837d5ff8      newvg	active
emc_clari0_85       00c95c90837d612f      newvg	active

Run the following command to trigger DMP discovery of the devices:
```
# vxdisk scandisks
```

After the discovery completes, the disks are shown as in use by LVM:

# vxdisk list

. . .
emc_clariion0_84 auto:LVM        -        -    LVM
emc_clariion0_85 auto:LVM        -        -    LVM

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