SVC CLI Commands

SVC Initial Setup

There are two ways to manage the SVC, with a GUI and though a Command Line Interface (CLI). This page discusses CLI commands, but it is not intended to be an exhaustive list of those commands and parameters, IBM has provided some good manuals and redbooks for that. This is just intended to give a flavour of the commands and how they could be used to define and manage an SVC cluster.

To set up a new cluster, you need to start in the machine hall with the physical SVC node. This work is normally done by an IBM engineer, but the process goes like this -

  • Connect a laptop or notebook to the Technician port on the back of the SVC appliance
  • Start up a browser and it should automatically connect to the default IP address for a new SVC, which is
  • An initial configuration screen will appear, click on 'first node on new system'.
  • Fill in the IP address information for the SVC cluster and hit enter.
  • A message 'system is created successfully' should appear.
  • click 'close' and a web server will start up, which will ask you to disconnect from the technician port.
  • You can now connect to the SVC cluster from any point in the network that is attached to the SVC management.

The first time you log onto the SVC you will be logged in as 'supervisor' and the default password in passw0rd. You will be immediately asked to change that password.

Using CLI Commands to manage the SVC

There are two basic types of SVC CLI commands:

  • svcinfo will list out information about the SVC and its components
  • scvtask will actually make changes to the SVC

Adding nodes to a cluster

Now that you have defined a basic cluster, you will want to add more nodes to it. Start by listing out all the unattached nodes

svcinfo lsnodecandidate

this will list out all SVC nodes that have not been assigned to clusters yet. The next task is to add one of these nodes to your cluster, and you identify it by either its WWN or panelname, which is straightforward, except that they are called id and node-cover-name in the lsnodecandidate listing.

So you add a new node with either

svctask addnode -panelname node-cover-name -iogrp io_grp1


svctask addnode -wwnodename id -iogrp io_grp1

Managing mDisks and MDGs

An mDisk corresponds to a LUN as presented by the controller of the attached storage subsystem. The detectmdisk command will rescan the system if you don't see LUNs on the system that you expect to be there.

svctask detectmdisk

To list out visible but unattached LUNs use the command

svcinfo lsmdiskcandidate -delim|

The -delim| parameter separates the fields in the command output with a | rather than a lot of spaces, so the output will hopefully not span lines. If you wanted to see all the managed disks then the command to use is lsmdisk.

Next you need to define a managed disk group with the command

svctask mkmdiskgrp -name MDGDS4FC001 -ext 256 -mdisk mdisk2

In this case, I'm creating an MDG called MDGDS4FC001 with a 256 MB stripe size (the default is 1GbB) and adding an mdisk called mdisk2 to it. You can add more mdisks by separating them with commas in the command above or you can add them to an existing MDG with the command

svctask addmdisk -mdisk mdisk3 MDGDS4FC001

To check out the status of a managed disk group use the command

svcinfo lsmdiskgrp -delim|

Managing vDisks

Now you have your managed disks placed into a managed disk group and all the space split into 256MB extents. Next you need to format those extents up into a virtual disk that you can present to a host. To do this, use the command.

svctask mkvdisk -mdiskgrp MDGDS4FC001 -iogrp io-grp0 -size 500 -vtype striped -unit gb -name VDAIX000

Here I'm creating a 500GB VDisk called VDAIX000 from the extents in MDGDS4FC001, and defining it to the SVC nodes in IO group 0.

Once you define some VDisks you can list them out with

svcinfo lsvdisk -delim|

or check out a specific VDisk with

svcinfo lsvdisk VDAIX000|

Managing Hosts

Next, you need to define your hosts to the SVC, but before you can do that, you need to know the WWPNs for the HBAs. Exactly how you do that will depend on what the host types are, so I'm going to assume that you know how to do this. There is a SVC Host Attachment Guide that will help you here.

Start by listing out all the unattached HBA ports that are zoned to the SVC. This command wil check that your host is visible and will list out both its WWPNs.

svcinfo lshbaportcandidate

The port names will be 16 HEX digits like


Check that you can see the WWPNs that you are expecting, then define the host using

svctask mkhost -a name P1201234 -hbawwpn 10000000DE1A34F2

Here I'm creating a host definition for server P1201234 and connecting it with one port. You can add both WWPNs in the command above by separating them with a colon, or you can add the second using

svctask addhostport -hbawwpn 10000000DF1045A2 P1201234

You can check to status of all the hosts, or an individual host with these commands

svcinfo lshost
svcinfo lshost P1201234

Finally, map the virtual disk to the host

svctask mkvdiskhostmap -host P1201234 VDAIX000

SVC CLI Command listing

You can list out all the available SVC CLI commands with the help facility -?. -h also works. You can get detailed help on any command by entering the help character after the command as shown below.

svcinfo -?               (list all info commands)
svcinfo commandname -?   (list the parameters for a specific info command)
svctask -?               (list all task commands)
svctask commandname -?   (list the parameters for a specific task command)

svcinfo commandname -filtervalue? will show what output formatting filters are available for that command and lets you reduce the level of output

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