Data ONTAP Cluster-Mode Fundamentals – Notes

*This is for version 8.1

Some definitions

LS Mirror = Load-Sharing Mirror

DP Mirror = Data-Protection Mirror

N-Blade = Network Blade

D-Blade = Data/Disk Blade

“Clients connect into a node’s N-blade which contains the networking stack – specifically the CIFS, and NFS protocols. The D-blade handles the client requests to and from the disk system and contains WAFL, RAID and the storage layer.”

Notes

Four features that distinguish Data ONTAP Cluster-Mode from Data ONTAP 7-Mode:

i. Transparent data movement

ii. Global Namespace

iii. Scalable performance

iv. Onboard antivirus support

The following list describes the new technologies introduced by Data ONTAP Cluster-Mode:

Transparent data movement, scalable performance, global namespace

You can perform a nondisruptive upgrade from Data ONTAP 8.0.2 to Data ONTAP 8.1!

McAfee and Sophos are the antivirus engines supported by Data ONTAP 8.1.

The following five resources can be shared by multiple cluster virtual servers:

Disks, Nodes, Network ports, Cluster logical interfaces, Aggregates

The following five resources are associated with exactly one cluster virtual server:

Data logical interfaces, volumes, mirrors, NFS services, CIFS services

A data logical interface is visible to NFS and CIFS clients.

Two attributes needed when creating a cluster virtual server:

Root volume and Aggregate

A cluster virtual server can have multiple volumes.

Creating a cluster virtual server also creates a namespace.

Creating a cluster virtual server also creates a root volume for its namespace.

A cluster virtual server cannot share a root volume with another cluster virtual server.

A cluster virtual server can share an aggregate with another cluster virtual server.

In clustershell, two ways to determine the available commands in a command directory:

The “?” key and the TAB key

The TAB key is the way to determine the possible values of the parameters of a command.

When creating an aggregate, the following three attributes can be specified:

RAID type, Disk count, Node(s)

An aggregate can be renamed after it is created.

An aggregate cannot be moved to a different node after it is created.

When creating a flexible volume, the following attribute determines the volume’s position in the namespace:

Junction path

A volume can be moved to a different node after it is created.

A volume can be removed from a namespace without being deleted.

Data ONTAP 8.1 Cluster-Mode supports unified storage architecture.

A type data logical interface will transport CIFS requests between a CIFS client and Data ONTAP storage.

A CIFS share can be created to provide access to…

- a nonroot volume

- a read-write volume

- a Snapshot copy

If the root volume of a namespace is NFS-mounted as “/”, and a write request arrives at an N-blade whose node houses an LS mirror of the target volume…

The write request remains local on the D-blade of this same node and the write fails!

If the root volume of a namespace is NFS-mounted as “/.admin”, and a write request arrives at an N-blade whose node houses an LS mirror of the target volume…

The write request is sent to the D-blade of the node that houses the read/write volume, and the write is done there!

When moving a volume, the following attribute is specified to determine the destination of the volume move operation:

Aggregate

When moving a volume…

- The volume’s position in the namespace is unaffected.

- All writes from an NFS client to the volume continue

DP mirrors…

- DP mirrors may be out of sync with LS mirrors of the same volume

- DP mirrors are not used for load balancing of read requests

The cluster show clustershell command shows all nodes in the cluster.

The following two clustershell commands give the best clues as to whether storage is online or offline in a cluster:

storage aggregate show

volume show