Migrating between DMP and HP-UX native multi-pathing


Migrating between DMP and HP-UX native multi-pathing
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Note:

Migrating from one multipath driver to the other overwrites the existing Powerfail Timeout (PFTO) settings for the migrating device. It will take the default PFTO setting for the multipath driver that it is migrated to.

You can use the vxddladm addforeign and vxddladm rmforeign commands to migrate a system between DMP and HP-UX native multi-pathing. These procedures migrate devices in the /dev/disk and /dev/rdisk directories

Note:

Before migrating between DMP and HP-UX native multi-pathing, ensure that no applications are accessing VxVM volumes. Migration is not supported without first stopping any applications that are using the volumes.

If the migration involves a currently booted disk, you must reboot the system. Specifying the - r option with the vxddladm addforeign command and the vxddladm rmforeign command, automatically reboots the system.

See the Storage Foundation Release Notes for limitations regarding rootability support for native multi-pathing.

To migrate from DMP to HP-UX native multi-pathing

Stop all the volumes in each disk group on the system:
```
# vxvol -g diskgroup stopall
```

Use the following commands to initiate the migration:

# vxddladm addforeign blockdir=/dev/disk chardir=/dev/rdisk
# vxconfigd -kr reset

For migration involving a current boot disk, use:

# vxddladm -r addforeign blockdir=/dev/disk chardir=/dev/rdisk

Restart all the volumes in each disk group:

# vxvol -g diskgroup startall

The output from the vxdisk list command now shows only HP-UX native multi-pathing metanode names, for example:

# vxdisk list

DEVICE    TYPE           DISK   GROUP   STATUS
disk155   auto:LVM       -      -       LVM
disk156   auto:LVM       -      -       LVM
disk224   auto:cdsdisk   -      -       online
disk225   auto:cdsdisk   -      -       online
disk226   auto:cdsdisk   -      -       online
disk227   auto:cdsdisk   -      -       online
disk228   auto:cdsdisk   -      -       online
disk229   auto:cdsdisk   -      -       online

When HP-UX native multi-pathing is configured, no DMP metanodes are configured for the devices in the /dev/disk and /dev/rdisk directories. As a result, the vxdisk list command only displays the names of the HP-UX native multi-pathing metanodes, and cannot display legacy names for the devices.

To migrate from HP-UX native multi-pathing to DMP

Stop all the volumes in each disk group on the system:
```
# vxvol -g diskgroup stopall
```

Use the following commands to initiate the migration:

# vxddladm rmforeign blockdir=/dev/disk chardir=/dev/rdisk
# vxconfigd -kr reset

For migration involving a current boot disk, use:

# vxddladm -r rmforeign blockdir=/dev/disk/ chardir=/dev/rdisk/

Restart all the volumes in each disk group:

# vxvol -g diskgroup startall

The output from the vxdisk list command now shows DMP metanode names according to the current naming scheme. For example, under the default or legacy naming scheme, vxdisk list displays the devices as shown.

# vxdisk list

DEVICE    TYPE           DISK   GROUP   STATUS
c2t0d0    auto:LVM       -      -       LVM
c3t2d0    auto:LVM       -      -       LVM
c89t0d0   auto:cdsdisk   -      -       online
c89t0d1   auto:cdsdisk   -      -       online
c89t0d2   auto:cdsdisk   -      -       online
c89t0d3   auto:cdsdisk   -      -       online
c89t0d4   auto:cdsdisk   -      -       online
c89t0d5   auto:cdsdisk   -      -       online

Under the new naming scheme, vxdisk list displays the devices as shown.

# vxdisk list

DEVICE    TYPE           DISK   GROUP   STATUS   
disk155   auto:LVM       -      -       LVM
disk156   auto:LVM       -      -       LVM
disk224   auto:cdsdisk   -      -       online
disk225   auto:cdsdisk   -      -       online
disk226   auto:cdsdisk   -      -       online
disk227   auto:cdsdisk   -      -       online
disk228   auto:cdsdisk   -      -       online
disk229   auto:cdsdisk   -      -       online