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 -
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.
There are two basic types of SVC CLI commands:
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
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
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.
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 1GB) 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|
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|
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.
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 P1201234
Finally, map the virtual disk to the host
svctask mkvdiskhostmap -host P1201234 VDAIX000
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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