Saturday, May 18, 2013

Virtual Data Mover (VDM)

What is a VDM?
-It is a feature that allows the separation of CIFS servers and their associated environment into virtual containers
-Enables replication of CIFS environments from a primary site to a secondary site without impacting server access
-Allows the movement of CIFS servers from one Data Mover to another
-VDMs store dynamic configuration data such as; local groups, shares, security credentials, audit logs, home dir information, kerberos

-Easier management of CIFS servers
-Provides server isolation and security
-CIFS servers within a VDM can be moved from one physical data mover to another without changing the share configurations

Key Concepts:
-A VDM can contain one or more CIFS servers
-Atleast one interface must be available for each CIFS server that is created
-CIFS servers in each VDM have access only to the filesystems mounted to that VDM
-In contrast, a physical data mover supports NFS and CIFS servers
-The UserMapper configuration is at the physical data mover level
-VDMs exist within a directory structure on a physical data mover's root file system, with VDM configuration information being stored in the root file system

Four states of VDMs:
Loaded: Fully functional active VDM with file system being loaded in read/write state
Mounted: In this state, the file system is mounted read only and CIFS servers are not active
PermUnloaded: The VDM file system is not mounted on the Data Mover
TempUnloaded: This is used to stop activity temporarily in preparation for replication

Creating a Loaded VDM:
Step:1 Create a VDM in a loaded state with name 'vdm02'

nas_server -name vdm02 -type vdm -create server_2 -setstate loaded

To create a VDM in a loaded state with root file system of default size being 128 MB

nas_server -name vdm02 -type vdm -create server_2 -setstate loaded pool=clar_r5_performance

Step:2 Mount the above created file system

Create mountpoint for the file system in VDM

server_mountpoint vdm02 -create /mntvdm

Mount the file system

server_mount vdm02 fs01 /mntvdm

Step:3 Configure CIFS for VDM

server_cifs vdm02 -add compname=hippodata,,interface=cge0-2

Step:4 Join the CIFS server to the domain

server_cifs vdm02 -join compname=hippodata,,admin=administrator

Step:5 Create CIFS shares

server_export vdm02 -protocol cifs -name vdmroot /mntvdm

Moving a VDM:
To move a VDM from one data mover to another

nas_server -vdm vdm02 -move server_3

For this to happen:
-target data mover should have identical interface names to the source
-target data mover should not have CIFS servers with the same name as the source

Remane a VDM:
nas_server -rename vdm02 vdm01

Deleting a VDM:
nas_server -delete vdm01
Read more: