zOS support

[VitekVlcek-Broadcom]

It would be great if Feilong supported zOS lifecycle, where zOS is 2nd level zVM guest:

1. IPL zOS,
2. Stop zOS
3. invoke MVS commands (D IPLINFO, ...) and capture their response

My understanding is that Feilong runs a zlinux under zVM, what it is resource consumption of this image (average CPU utilization, Memory, Disk). In my case I would ideally avoid extra VM with zlinux to reduce memory and CPU resources because I'm running zVM under zD&T (zPDT)

I already have a POC version implemented off the Feilong project here is an architecture diagram:

• In my case I can have many instances of zVM each representing a parallel sysplex, that could be provisioned by a developer, therefore I prefer to avoid zlinux on each zVM and instead have the majority of components off the zVM.
• Ideally, I would like to combine LXC and observer into a single VM to minimize overhead of infrastructure
• LXC is used to send commands such as: Q NAMES, CP SEND CP ZOS1 CP IPL ..., CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER ...
• OBSERVER - IUCV2Socket - capture console messages sent from zOS vms and forward them via a network socket to a CLI that runs on linux, POC is based on
  • Managing z/OS guests on z/VM with IBM Operations Manager for z/VM interesting article describing how to interact with zOS master console using CP VINPUT VMSG xxx commands and how to capture responses using CP SET OBSERVER ...
  • Sample REXX program to listen on a TCPIP socket
  • Sample REXX program to trap IUCV messages using WAKEUP

[bjhuangr]

currently, feilong rely on the IUCV channel to communicate with SMAPI request servers, so it has to stay in the same z/VM system. We don't have performance data like cpu consumption of feilong services, but according to our daily use, it's relatively a light weight service

[jichenjc]

from the picture I think you are proposing LXC and other CMS related components to hosting feilong like Linux but provisioning z/OS Is not hard depend on the LXC related item, is that correct?

[VitekVlcek-Broadcom]

LXC is used to issue CP commands Q NAMES, CP SEND CP ZOS1 CP IPL ..., CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER ... from a linux VM running off the zVM. In this scenario, Feilong is not running in zLinux under zVM. This picture covers only the start/stop scenario of zOS. Provisioning of zOS is out of scope. We could discuss late what it means to provision zOS it is not that easy like in case of linux, provisioning involves multiples volumes.

[jichenjc]

correct, that's what I am expecting about z/OS itself ,we can talk about at next meeting if you can record/show the env that you have now it might be easier to understand

Thanks~

---

From: Vitek Vlcek @.> Sent: Thursday, October 12, 2023 8:14 PM To: openmainframeproject/feilong @.> Cc: CHEN JI @.>; Comment @.> Subject: [EXTERNAL] Re: [openmainframeproject/feilong] zOS support (Issue #751)

LXC is used to issue CP commands Q NAMES, CP SEND CP ZOS1 CP IPL .. . , CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER .. . from a linux VM running off the zVM. In this scenario, Feilong is not running in zLinux under zVM. This picture ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. https://us-phishalarm-ewt.proofpoint.com/EWT/v1/PjiDSg!2A-qKrTUgROxke9zkqrvJs6yI8Q_iH1OjKqdnawhJKhS7JHeoCcjUMUMy5lLDLq1OvNLpVJdCC5YjG9howfYQK8Qi2FTSyHSfw0TABjigR_bAD65C6hd$ Report Suspicious

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LXC is used to issue CP commands Q NAMES, CP SEND CP ZOS1 CP IPL ..., CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER ... from a linux VM running off the zVM. In this scenario, Feilong is not running in zLinux under zVM. This picture covers only the start/stop scenario of zOS. Provisioning of zOS is out of scope. We could discuss late what it means to provision zOS it is not that easy like in case of linux, provisioning involves multiples volumes.

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[mfriesenegger]

@VitekVlcek-Broadcom We mentioned this issue during today's Feilong TSC meeting. I see @jichenjc suggested demoing the env. Is this something you would like to do for the January Feilong meeting?

[Bischoff]

Hi Vitek, I have seen with interest your demo of your first PoC relying on LXC.

My observations:

• I was first confused by "LXC" name, as it is a well known containers system under Linux :smile_cat:
• What you do with LXC could also be done via s3270, the "scripting" version of x3270 terminal emulator: send CP commands, analyze output...
• I am quite confused whether zthin component of Feilong needs IUCV to communicate with SMAPI. @bjhuangr says above it does, but 1) I think SMAPI can also be driven with IP sockets, and 2) we accidentally got Feilong to work while we forgot IUCV settings :thinking: . If IUCV is not mandatory, then you could put zthin or even a full Feilong outside of the s390 host.
• Your approach is very different in essence from what Feilong does: your LXC PoC uses CP commands to start and stop an existing z/VM guest, while feilong can deploy a new VM from a preexisting image, by manipulating the z/VM directory via SMAPI. Feilong can also start and stop existing VMs BTW.
• The fact that the approach is different does not mean you cannot reach the same goal with LXC and Feilong - it's just in a very different way :smile_cat: .

• However, I do not know whether Feilong assumes it is a Linux system that is being deployed. For example you can access the IP address of the guest, I am not sure how this is achieved and if Feilong needs to access the guest OS to achieve that.

  If I were you, I would just try to start and stop an existing zOS system with Feilong, to see if that works.

  I hope that helps.

[mfriesenegger]

Hello Eric,

• I was first confused by "LXC" name, as it is a well known containers system under Linux 😸

I believe this LXC - https://www.vm.ibm.com/download/packages/descript.cgi?LXC - predates the Linux LXC technology that you are thinking of.

[jichenjc]

I am quite confused whether zthin component of Feilong needs IUCV to communicate with SMAPI. @bjhuangr says above it does, but 1) I think SMAPI can also be driven with IP sockets, and 2) we accidentally got Feilong to work while we forgot IUCV settings 🤔 . If IUCV is not mandatory, then you could put zthin or even a full Feilong outside of the s390 host.

IUCV is used for Linux VM communication, SMAPI is for VM management through z/VM DIRMAINT/CPU SMAPI is pure socket thing and feilong covers both SMAPI and IUCV for different purpose you can create VM USER DIRECT through DIRAMINT but it might not fit feilong whole purpose which covers Linux part as well

However, I do not know whether Feilong assumes it is a Linux system that is being deployed. For example you can access the IP address of the guest, I am not sure how this is achieved and if Feilong needs to access the guest OS to achieve that.

the access to IP address is beyong feilong scope, we used to use ssh to do management but this means this need management entity need ssh to VM which is some case it's security concern and sometimes the network is not reachable at all, so we use IUCV instead

If I were you, I would just try to start and stop an existing zOS system with Feilong, to see if that works.

if it's z/VM guest, I see no reason why those 2 are not supported (as it will be z/VM Start/Stop through Image_Activate and Deactivate API which is pure SMAPI thing which interpret as CP command only)

[Bischoff]

Thanks for the clarifications @jichenjc. The schema at https://cloudlib4zvm.readthedocs.io/en/latest/architecture.html#internal-architecture had mislead me, I suggest in another issue to fix it.

To summarize this discussion:

• handling z/OS VMs from Feilong would work as long as we use only the SMAPI part. That includes starting and stopping VMs.
• to do the same thing with z/OS as Feilong does with Linux, one would need to implement the equivalent functionality. The most "Feilongish" way would be IUCV, but you could continue with LXC, I guess
• but if you are to continue with LXC, is there still a point to rely on Feilong's SMAPI part? Yes, if provisioning becomes part of your scope.

These are just personal thoughts. I do not represent the Feilong project in any way.

[VitekVlcek-Broadcom]

Thanks @Bischoff for the summary, I would love to use SMAPI instead of LXC however. LXC is used for:

1. start/stop zVM - there should be API calls (based on your reply)
2. send a command to a VM console eg: Q NAMES, CP SEND CP ZOS1 CP IPL ..., CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER ... - is there a SMAPI endpoint for it?

[jichenjc]

start/stop zVM - there should be API calls (based on your reply)

yes, this is easier , Image_Activate/Deactivate I shared above

send a command to a VM console eg: Q NAMES, CP SEND CP ZOS1 CP IPL ..., CP SEND CP ZOS1 VINPUT VMSG D IPLINFO, CP SET OBSERVER ... - is there a SMAPI endpoint for it?

we can create a customerized API doing so https://www.ibm.com/docs/en/zvm/7.3?topic=programming-creating-custom-apis

we used to have a API that can do so and it trigger some security concern as if something like CP <input command> then it's able to do everything which we don't want