vsdnode Command

Purpose

Define virtual shared disk information for a node or series of nodes.

Syntax

vsdnode: node_number… adapter_name min_buddy_buffer_size
: max_buddy_buffer_size max_buddy_buffers
: vsd_max_ip_msg_size [cluster_name]

Description

Use this command to make the specified nodes virtual shared disk nodes and to assign their virtual shared disk operational parameters. If this information is the same for all nodes, run this command once. If the information is different for the nodes, run this command once for each block of nodes that should have the same virtual shared disk information.

You can use the System Management Interface Tool (SMIT) to run the vsdnode command. To use SMIT, enter:

smit vsd_data

and select the virtual shared disk Node Information option.

Flags

-f: Forces the removal of any virtual shared disks defined on this global volume group.

Parameters

node_number

Specifies the node or nodes whose virtual shared disk information is to be set. The value you specify for node_number must match a valid RSCT remote peer domain node number.

adapter_name

Specifies the adapter name to be used for virtual shared disk communications for the nodes specified. The adapter name must already be defined to the nodes. Note that the nodes involved in virtual shared disk support must be fully connected so that proper communications can take place. Use ml0 to specify that the virtual shared disk device driver transmits data requests over the SP Switch. The ml0 adapter will be used the next time the virtual shared disk device driver is loaded.

min_buddy_buffer_size

Specifies the smallest buddy buffer a server uses to satisfy a remote request to a virtual shared disk. This value must be a power of 2 and greater than or equal to 4096. The suggested value is 4096 (4 KB). For a 512 byte request, 4 KB is excessive. However, recall that a buddy buffer is only used for the short period of time while a remote request is being processed at the server node.

max_buddy_buffer_size

Specifies the largest buddy buffer a server uses to satisfy a remote noncached request. This value must be a power of 2 and greater than or equal to the min_buddy_buffer_size. The suggested value is 262144 (256 KB). This value depends on the I/O request size of applications using the virtual shared disks and the network used by the virtual shared disk software.

max_buddy_buffers

Specifies the number of max_buddy_buffer_size buffers to allocate. The virtual shared disk device driver will have an initial size when first loaded, and then will dynamically allocate and reclaim additional space as needed. The suggested value is 2000 256 KB buffers.

Buddy buffers are only used on the servers. On client nodes you may want to set max_buddy_buffers to 1.

Note: The statvsd command will indicate if remote requests are queueing waiting for buddy buffers.

vsd_max_ip_msg_size

Specifies the maximum message size in bytes for virtual shared disks. This value must not be greater than the maximum transmission unit (MTU) size of the network. The recommended values are:

61440 (60KB) for a switch
8192 (8KB) for jumbo frame Ethernet
1024 (1KB) for 1500-byte MTU Ethernet

cluster_name

A cluster name must be specified for server nodes that will be serving concurrently accessed shared disks. The cluster name can be any user provided name. A node can only belong to one cluster. For example, when you have a concurrent access environment, the two servers for the CVSD must both specify the same cluster name.

Note: The cluster_name is required only for SSA (Serial Storage Architecture) disks.

Security

You must have root authority to run this command.

Restrictions

The node specified on this command must already belong to a peer domain, and you must issue this command from a node that is online in the peer domain. To bring a peer domain online, use the startrpdomain command. To bring a particular node online in an existing peer domain, use the startrpnode command. For more information on creating and administering an RSCT peer domain, refer to RSCT Administration Guide.

Examples

The following example defines information for a switch network and nodes 1 through 8.

vsdnode 1 2 3 4 5 6 7 8 ml0 4096 262144 128 61440

Location

/opt/rsct/vsd/bin/vsdnode