Typically, a console for an LPAR is launched via an HMC, via GUI or CLI (vtmenu or mkvterm). A console depends on the availability of an HMC. During an HMC update or problems with the HMC, you may not be able to connect to an LPAR console.
Relatively unknown is the ability to configure a console to an LPAR via a virtual I/O server. If the HMC is not available, then a console can be started via the virtual I/O server. No configuration is required on the client LPAR! By default, each client LPAR has 2 virtual serial server adapters (slots 0 and 1). If you configure an associated client adapter on a virtual I/O server, you can use it for a console connection.
On the virtual I/O server one needs only an unused virtual slot (here slot 45). The client LPAR has the LPAR ID 39. The virtual serial client adapter can be created with the following command:
hmc01 $ chhwres -m ms02 -r virtualio --rsubtype serial -o a -p ms02-vio1 -s 45 -a adapter_type=client,remote_lpar_name=aix02,remote_slot_num=0,supports_hmc=0 hmc01 $
Now you can always start a console for the LPAR via the virtual I/O server:
ms02-vio1 :/home/padmin> mkvt -id 39 AIX Version 7 Copyright IBM Corporation, 1982, 2018. Console login: root root's Password: XXXXXX aix02 AIX 7.2 powerpc Last unsuccessful login: Mon Mar 18 23:14:26 2019 on ssh from N.N.N.N Last login: Wed Mar 27 20:19:22 2019 on /dev/pts/0 from M.M.M.M [YOU HAVE NEW MAIL] aix02:/root> hostname aix02 aix02:/root>
The command mkvt on the virtual I/O server corresponds to the command mkvterm on the HMC. Here the desired partition must be specified by the LPAR-ID. Terminating the console works as usual with “~.“, Or if you are logged in via SSH on the virtual I/O server with “~~.“.
Alternatively, you can also end a console session with the command rmvt:
ms02-vio1:/home/padmin> rmvt -id 39 ms02-vio1:/home/padmin>
The following message appears in the console and the console is closed:
Virtual terminal has been disconnected. $
With the LPAR tool, the console can of course be set up even easier. The virtual serial adapter on the virtual I/O server can be created with the command “lpar addserial“, a manual login to the HMC is not necessary for this to work:
$ lpar addscsi -c ms02-vio1 45 aix02 0 $
The “-c” option means “create client adapter”. The command also creates the adapter in the profile. The success of the action can be checked by “lpar vslots“, showing all virtual adapters of an LPAR:
$ lpar vslots ms02-vio1 SLOT REQ TYPE DATA 0 1 serial/server remote: -(any)/any status=unavailable hmc=1 1 1 serial/server remote: -(any)/any status=unavailable hmc=1 2 0 eth PVID=1 VLANS=- XXXXXXXXXXXX ETHERNET0 3 1 eth TRUNK(1) IEEE PVID=1 VLANS=201 XXXXXXXXXXXXX ETHERNET0 ... 45 0 serial/client remote: aix02(39)/0 status=unavailable hmc=0 ... $
Starting the console then proceeds as usual by logging in as padmin on the virtual I/O server and the command mkvt.
Caution: The console session through the virtual I/O server should always be terminated when it is no longer needed. You can not terminate it from the HMC! Here is the attempt to start a console using the HMC, while the console is already active using the virtual I/O server:
$ lpar console aix02 Open in progress A terminal session is already open for this partition. Only one open session is allowed for a partition. Exiting.... Attempts to open the session failed. Please close the terminal and retry the open at a later time. If the problem persists, Please contact IBM support. Received end of file, Exiting. Connection to X.X.X.X closed. $
Even rmvterm does not help:
$ lpar rmvterm aix02 /bin/stty: standard input: Inappropriate ioctl for device $
Conversely, no console can be started using the virtual I/O server if a console is active using the HMC:
ms02-vio1:/home/padmin> mkvt -id 39 Virtual terminal is already connected. ms02-vio1:/home/padmin>
So always make sure that the console is terminated.