I’m also creating tools that can be useful for you, this includes an nmon grapher called nmon2graphite. One off my very popular tool is called lsseas. This one show details about the SEAS I had the chance to participate in the writing of the lastest Redbook about PowerVC. This one is very complete and useful if you are a expert or a PowerVC beginner have a look on it !
My experience from the field after using PowerVC during one year since the very first release (I’m today using it in production) 1 – We will talk about how PowerVC is managing the Virtual I/O Server and particularly the Sharded Ethernet Adapters , you’ll see in this section that there a couple of things that are not so obvious and that needs to be clarified 2 – Same story for storage management, here I’ll only talk about what I really now. I’m using Storage Volume controller with San brocades switches and there are a couple of things to know on how configuration and using the Storage in PowerVC 3 – We will here details how the activation is working. You don’t need to know that to use powervc but it can be useful to know how it really works and what PowerVC is doing at the activation time 4 – I discover a couple of interesting things while using PowerVC, one of this thing is how disks PVID are managed 5 – As cloud it will be the official activation engine for AIX I’ll try here to give you some details on how it works and how to configure it (the documentation on the official website has a lot of missing things)
Many customers have a slot numbering convention. In a PowerVC environment this slot numbering convention can’t be maintain. One the image below (which is an output of the tool lsseas showing details about Shared Ethernet Adapter) you can see that this SEA was created with four VEA, a fifth one was added automatically be PowerVC But what about buffer (as far as I know almost all customers change the SEA VEA buffer size)
As PowerVC is creating the Virtual Ethernet Adapter used by SEA for you, this one are created with default attributes Prepare you Virtual I/O Servers before managing them with PowerVC On the example on the screen you can see that you can use the chdef (I said chdef not chdev) to change the default value of the attributes of the Virtual Ethernet Adapters. This is also applicable to any other devices (vscsi adapter, virtual fibre channel adapters and so on). In the next version of the Virtual I/O Servers you can also use the rules. Rules is a new command that allow you to define how adapters are created, but is also checking that this attributes are ok after during the life of the Virtual I/O Server. Just run a rules –o diff and rules dash o deploy to check the attribute
I assume that most of you are using Shared Ethernet Adapter in sharing mode. Unfortunatly in the current version of PowerVC there is a bug. When PowerVC is removing the last vlan of a VEA it also remove the adapter if this one is not needed anymore). In the case of an SEA in sharing this one needs to have at least two VEA available to work …. And PowerVC keep at least only on VEA (if you reboot the virtual I/O Server at this the the sea will be in Define state) and you’ll have to correct this by hand There is a way to disable this feature to keep the vlan on the Shared Ethernet adapter and to keep each VEA even if there is no vlan on it) Restart PowerVC after doing this
Reminder any configuration of nova configuration (nova.conf and nova.conf for each host) require a reboot of the PowerVC services.
When you add a vlan on PowerVC you have to tell each SEA will be used (you can have differents seas for different network zones). So be carefull : - At vlan creation - When adding host (I’m today using more than three hundred vlan, so when adding one host I need to check all my already define vlan to tell which sea will be used for which vlan). - I have a script to automate this action (ask me if you want it)
Let’s now start with storage tips and tricks. I’ll talk here about a full NPIV environement I have analyzed how PowerVC is creating zone and it’s not so simple to understand. The first thing is pretty easy is that obviously PowerVC will create at least one zone per Virtual fibre channel adapter. So if you choose dual per vios with two Virtual I/O server you’ll have at least four zones If you choose single per vios with two virtual I/O server you’ll have at least two zones This setting are in the configuration of the connectivity group There is also one hidden option in the Storage template this one is called “ use all available WWPNs for attachement”. We will check in the next slide what is doing this option
We will study the case of an SVC with two node and one I/O group (but same thing apply to other storage array) If you do no check the option : The redundancy will be ok as each node will be zoned You’ll only have one zone per WPPNs There is not spot and you’ll be in a multi fabric environment But you’ll get some warning on the SVC side (on the to have an ok state a wwpns must be zone on both SVC node), this is what we see on the image on the right One WWPNS = One zone = One node
If you check the option you’ll be surprise …. Or you will be surprised iff you have a lot of front end port available on you storage array or on you SVC. On the image below a SVC with 10 FE port is represented on the image PowerVC will create zone on all the port and on all the node So for one wwpns 5 ports fabric A on node A 5 ports fabric A on node B EQUAL ten zones per wwpns ! I am asking myself who is doing that. Maybe some customer have svc or san array with just 4 ports. It is usefull only if you don’t have too many ports available. If you are checking this option on a san array with a lot of front end ports …. You can have huge performance issue. I made the mistake myself and the result was that VM where create with sixteen or even worse thrity two paths. Check this option only if you exactly what it is doing on you storage array.
When you don’t check this option. PowerVC is spreading the zone on each available front end ports by using an internal algorithm. I don’t have all the details but the PowerVC developpement team told me that from end port will be choose depending on the number of available ports and depending on the name of the virtual machine. Today PowerVC is just using the first four available ports on the SVC. You can ask for a patch to use the others available ports
A few points to know about storage. 1 – If you are managing existing machines new luns will be automatically set in the default storage templates. 2 – If you are adding lun in a different storage template PowerVC will create the zones needed for this storage template at the time of creating this lun 3 – Be very very careful when creating VM, you can be stuck if you choose the wrong Storage template by this I mean: - If the storage template you are choosing is creating two many zone you can’t change it. The VM will be stuck forever in this storage templates 4 – On the other side if you choose a storage template that is not creating enough zone you can add a lun in another storage template and zones will be created at this time (all the existing lun will use the new zones created).
What we call the datasource is the input the activation engine is using to configure the Virtual Machine at boot time Both cloud-init and VSAE are taking this input to configure the Virtual Machine at the activation time This is done by using Virtual I/O Server virtual optic devices
Power vc for powervm deep dive tips & tricks
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PowerVC for PowerVM Deep Dive
Tips & Tricks
Aix System Engineer
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