Questions Log C:\FTSS\Webinars\2015-12-17 Care and Feeding of VIOS\QuestionsLog 2015_12_17 09_34.rtf
Extra Links:
POWER7 Virtualization Best Practices Guide:
AIX PERFORMANCE FAQ:
Replays of Jaqui’s Performance Presentations:
Audience Question:
Q: How do you do the upgrades if you have VIOs in Active Active mode?[Brad Brewer] [ [Q: 8:10 AM] [A: 8:17 AM]
A: You would have to fail over ( automatically or manually ) to one VIOS, then do the upgrade
Audience Question:
Q: Can you please share the Wiki Link?[Byron Herlong] [ [Q: 8:17 AM] [A: 8:18 AM]
A: the AIX VUG Wiki is:
Q: can you post up that version of the pdf you're displaying now? the one on the wiki has two slides per page, instead of just one per.[Howard Coles] [ [Q: 8:19 AM]
A: I believe that is happening next week
Q: Does the HWMA requirement for FW updates mean we will not be able to download FW files via SFTP and we will always have to go out to IBM.com to obtain FW files?[Jose Apolonio] [ [Q: 9:16 AM]
A: I believe that is the case but you would need to ask IBM. There is a section on firmware maintenance in each of the Power8 server Technical Overview Manuals and I see no mention of SFTP there.
Q: What is the best way to resolve thsimessage:"The command's response was not reconized. This may or may not indiscate a problem." I got this when mapping disk to a vhost. [Tom Geyer] [ [Q: 8:24 AM]
A: Check errpt to see if it gives any indications. You may see this for instance if filesystems fill up or if the vSCSI adapter is in an undefined state and so on.
Q: for the large send on VIO should I activate it only on the SEA or also for phisicallent( andEtherchannel ) ?[youssefchaib] [ [Deleted] [Q: 8:25 AM]
A: large send needs to be set on the SEA and the virtual Ethernet. It is usually set on by default on the adapter but you should still check. At more recent levels of AIX there is also the mtu_bypass option that sets it on the AIX LPAR interface.
Q: Can the HBA client setting with the same value than VIOs?[Dario Caputo] [ [Q: 8:19 AM] [A: 8:28 AM]
A: your question isn't cler
A: If you are referring to num_cmd_elems on the HBA, then it cannot be set above 256 on the VIO client. It can be set to higher values (even 4096) on the VIO server if the underlying disk subsystem supports it.
Audience Question:
Q: would these HBA settings also apply to all flash storage array? Should they go higher?[Kenny Perkins] [ [Q: 8:20 AM] [A: 8:29 AM]
A: There are some flash array specific recommendations. Please ask your storage technical focal, or support, for current recommendations. I have some, but they are from spring 2015. Might be a bit dated.
A: I have used some of these values (and higher) with the IBM flash 810, 820, 840 and 900. You need to check with your hardware vendor what values they will support. Additionally you should check with your application provider to see if they have whitepapers with recommendations – I have seen them for SAS and SAP plus some others.
Audience Question:
Q: Can multiple SEA's use 4095?[Hal Kussler] [ [Q: 8:31 AM] [A: 8:32 AM]
A: Each SEA failover pair has its own control channel, they are unique.
A: As of powervm 2.2.3 yes they can. See page 39 of where it says “The requirement has been removed for a dedicated control-channel Ethernet adapter and a VLAN ID for each SEA failover configuration.”
However, this is hardware, firmware and VIOS level dependent – Powervm 2.2.3, HMC 7.7.8, FW780 MMC/MHC – or higher
Audience Question:
Q: What if you have mutliple SEAs on a VIO? Do you need to define the different control channels for each SEA?[Amy Appel] [ [Q: 8:31 AM] [A: 8:32 AM]
A: Yes
A: Not if you are running 2.2.3 at the correct firmware on the correct hardware –Powervm 2.2.3, HMC 7.7.8, FW780 MMC/MHC – or higher
Audience Question:
Q: Rather than a pair of seas, can one have three or four seas, each with a different priority level, all using the same control channel?[Valerie Bright ] [ [Q: 8:49 AM] [A: 9:17 AM]
A: no, thectl channel is for a pair, no more, SEAs
A: See discussion on 2.2.3 changes above
Audience Question:
Q: Apparently one can have more than two VIOS/seas for the same vlan. They all use the same control channel?[Valerie Bright ] [ [Q: 8:43 AM] [A: 8:45 AM]
A: thats really two different things. SEAs use ctl channels, each pair needs its own. VLANS are unique to a IP network.
A: Read the Powervm 2.2.3 Enhancements redbook – it talks about this in a lot of detail. After 2.2.3 with the right firmware, etc the rules for control channels change and, if you don’t define one then the SEAs will use 4095
Audience Question:
Q: Is disabling of threads on the ethernet adapters recommended for mix of NPIV and shared ethernet VIOs?[Chris Cone] [ [Q: 8:26 AM] [A: 8:34 AM]
A: I've never seen that as a recommendation. Threads help SEA performance, in general, as does adequate CPU entitlement.
A: Disabling of threading is only recommended if you are running just the network on the VIO server. While the issue that requires threading is vSCSI I have not seen anything that recommends disabling threading if you are purely using NPIV with the network so I do not recommend it.
Q: Can one have separate pairs of VIOS's for prod and non-prod using the same vlan?[Valerie Bright ] [ [Q: 8:33 AM] [A: 8:36 AM]
A: hmm, vlans are unique to a network ( IP ) segmant. So, it really depends on quite a few things. A bit to deep to discus here.
A: Pretty sure that will cause you some conflicts but this is a design question to discuss with your network team.
Audience Question:
Q: Any preformance concern when creating 10 virtual adapter in VIOC vs creating 1000 virtual adapter in VIOC?[Seow Gin Goh] [ [Q: 8:36 AM] [A: 8:37 AM]
A: well, each v-adapter requires memory resources. So, you'd have to cover that need. It may take longer to boot and perform some comands in the VIOS.
A: My best guess is yes that these take some memory, however small it may be. I think they used to keep adapter definitions at the top of memory in a TCE (translation control entry) area. I can find references to the TCE in power5 where it was used for DMA to I/O devices. The IBM knowledge center says: “The maximum number of virtual adapters can be any value from 2 to 65,536. However, if you set the maximum number of virtual adapters to a value higher than 2048, the logical partition might fail to activate or the server firmware might require more system memory to manage the virtual adapters.” See:
Q: When creating VIOS/C if I specify the max Virtual adapter to be 10000,does the hypervisor allocate the memory resource for it or the 10000 is just a number?[Seow Gin Goh] [ [Q: 8:52 AM]
A; See above answer re memory needs for virtual adapters
Audience Question:
Q: Can VIOS 2.2.4.10 run on a Power6?[Valerie Bright ] [ [Q: 8:35 AM] [A: 8:39 AM]
A: I suggest you check the IBM FLRT and IBM Pre-Requisite sites. and
A: Also check the 2.2.4.10 readme at:
POWER6 support is dropped at AIX 7.2 – VIOS 2.2.4.10 is AIX 6.1 tl09 sp6 equivalent so POWER6 should be supported but check the readme and FLRT etc
Audience Question:
Q: How do you get the current settings...Does lsattr display these values ?[Dileep Nair] [ [Q: 8:25 AM] [A: 8:40 AM]
A: yes, but its a bit different syntax as padmin user
Audience Question:
Q: What happens if I don't remove an efix before running updateios? [Amy Appel] [ [Q: 8:40 AM] [A: 8:40 AM]
A: It will likely fail
A: If the efix is for a fileset that is being updated the update will fail. If the efix is not for a fileset you are updating then the updateios will most likely work. But it is better to be safe than sorry.
Q: What if the updateios did not fail? Am I ok?[Amy Appel] [ [Q: 8:41 AM]
A: I don’t know. I recommend running the after update checks to see if you have any missing filesets etc. You can also run flrtvc to make sure you have patched any security etc holes.
Q: Should I remove and readd the efix?[Amy Appel] [ [Q: 8:41 AM]
A: I always remove all efixes before updating AIX or a VIOS. I then run flrtvc after to see if I can reinstall the same efix or if I need to download a newer version. It all depends on whether the patches installed changed the filesets that the efix addresses.
Q: would be great to have your script(?)[Martin Dumont] [ [Q: 8:41 AM]
A: If you mean the save-viostuff.sh script it is on slide number 45.
Q: How to update oslevel in VIO server?[Arunchowdarykaricheti] [ [Q: 8:44 AM]
A: Slides 39-41 talk about how to deal with problems where the oslevel does not match what the VIO level says it should be. This should be done with great care and you should never do a blanket update from an AIX CD or repository.
Q: When should I use the '-install-' flag of the updateios command? Based on its man page, it seems that this is only required if you want to install additional filesets found at the source...[Daniel Olops] [ [Q: 8:44 AM]
I use it when I install updates from a directory similar to:
updateios -accept -install -dev /usr/local/soft/vios2232-fp27-sp2
It is what you use to install filesets or updates
Q: Can we update the VIO using the alt_disk_copy -b update_all option?[VasiliyGokoyev] [ [Q: 8:46 AM]
A: As far as I am aware you can use nim –o updateios or nim –o alt_disk_install. I am not sure about alt_disk_copy
Q: I thought IBM recommended never recommended to correct underlying OS to correct level?[Sunil Shivamallu] [ [Q: 8:47 AM]
A: I am recommending making sure you have no missing filesets or issues with them. IBM says not to use smitty install to do the updates and that is correct. I am recommending either removing problem filesets or updating them using updateios. This should be done very carefully. Over time if you have too many filesets in this condition then your updates will fail – I have seen this many times.
Q: what is a VCSWs ?[Chuck Leese] [ [Q: 8:53 AM]
A: VCSW stands for virtual context switch and refers to virtual processor hardware preemptions.
Q: What should be the relationship between the RAM memory and paging space in VIOs?[Dario Caputo] [ [Q: 8:55 AM]
A: It depends – I would use the vios performance advisor (part) to make sure you have plenty of memory. I normally run with 1 x 4GB page space (if on internal disk then it is mirrored) but it depends on your workload. Ideally your VIO will never page. Additionally run sysdumpdev –l and make sure that dumps go to real dump datasets and not the pagespace.
Q: What about dual HMC setup , while upgrading from 7.7.7.x to 7.7.9.x , need to one of HMC FSP connection to be taken down ?[Manish Kumar] [ [Q: 9:08 AM]
A: You need to look at the HMC readme for the level you are going from/to and read the instructions for those levels for dual HMCs.
Q: Are you seeing customers with HMC CR8 upgrading to 16GB RAM?[Amy Appel] [ [Q: 9:08 AM]
A: Yes my clients normally add the extra 8GB dimm – it is not expensive and makes a huge difference when multiple people are on the HMC. Also, the HMC is very GUI heavy today so the extra memory helps a lot.
Q: Jaqui mentioned get as much memory as possible. I also saw the CR9 has 16GB RAM but the CR8 came with 8GB RAM.[Amy Appel] [ [Q: 9:10 AM]
A: I believe there is an additional 8GB dimm you can add to your CR8.
Audience Question:
Q: will you be seinding this pdf to attendees?[sankarArumugam] [ [Q: 9:11 AM] [A: 9:14 AM]
A: it is on the wiki:
Audience Question:
Q: How do you determine which oslevel should be mapped to the ioslevel? [Wendy Smith-Wesley] [ [Q: 8:50 AM] [A: 9:18 AM]
A: I have an internal site that shows that, don't know if its public info. You can always run oslevel as root user to se what's installed
A; You can go to this link to get the VIOS to NIM master mapping which will get you most of the way:
Additionally, the readme for the VIOS install has the same information.
Q: My VIOS is at 2.2.3.3, FLRT recommended update to 2.2.3.50. Should I upgrade to the latest 2.2.4.*?[Jeremy Ho] [ [Q: 9:20 AM]
A: FLRT does not always recommend the very latest version as the developers wait for IBM engineering to make it the recommendation. 2.2.4 came out December 5 so the decision to upgrade will be a function of does it have something you need now and how comfortable are you putting in an update that is this recent.
Q: While upgrading HMC with dual HMC setup from , from 7.7.7.x to 7.7.9.x , need to one of HMC FSP connection to be taken down , which is painful. Is there a better way of doing ?
[Manish Kumar] [ [Q: 9:21 AM]
A: The document below has details on upgrading from 7.7.7 -
I don’t see anywhere that recommends taking an FSP connection down but you should check with IBM to be sure.
Q: Can AIX be upgraded to higher TL or SP than what comes with the VIO?[Scott Choi] [ [Q: 9:22 AM]
A: If you mean an AIX client LPAR then yes as long as the VIO is supported for that AIX level – you can check this on FLRT. As an example you can have a VIO at 2.2.3 (which is AIX 6.1 tl9) with clients running Linux, AIX 6.1 and AIX 7.1.
Q: How do we get the audio for this session as well? Lots of tips and good comments that are not on the slides.[Marsha Friedli] [ [Q: 9:22 AM]
A: Joe should be uploading the audio but if it is not good quality there is an older version of this uploaded to my movies site (which uses youtube) at
Audience Question:
Q: Is there a way of automating software maintenance? Get notifications about compliance and stuff like that?. I mean something like the compliance plug in that there was in Director?[Pablo Pereira] [ [Q: 9:16 AM] [A: 9:23 AM]
A: Might want to take a look at PowerSC
A: Also recommend you check out FLRTVC – you can download it and use cron to runit regularly to check for hipers and security issues -
Q: When using PowerVC, it creates a single-target single-zone configuration in the fabric switches & SVC. This creates 4 paths in AIX per LUN, rather than the typical 8. Since NPIV is active-active across both VIOSes, I've seen powering one VIOS does, and severing HBA connections therein, cause outages to DB2 running in AIX LPAR's on the back-end. Have you seen this?[John Otto] [ [Q: 9:24 AM]
A: No I have not but you may want to check the powervcredbook – there are some notes on Page 47. Otherwise I would open a PMR to see if this is behaving correctly.
Q: I have 4 VIOS, 2 of those are in cluster with SSP defined, is concurrent update supported in that scenario? i.e. Do I need to shutdown the client using SSP or I can upgrade the first VIO1, then VIO3 without affecting the client?[Jeremy Ho] [ [Q: 9:26 AM]
A: You will need to check the readme file for the VIOS level you are going to. There are specific instructions in it for SSPs.
Q: whats the average time per Power8 frame per year to do this VIOS housekeeping?[Jack Hyde] [ [Q: 9:27 AM]
A: This is an it depends. Depends on how many VIO servers you have per frame and so on. If you keep it current and use scripts and cron jobs to do the checking then it should be minimal. It normally takes me less than an hour to upgrade each VIO server but I stay current. HMC’s take longer because they get rebooted with each update and each reboot takes around 20 minutes.
Audience Question:
Q: what is the wiki link?[Cynthia Culbreath] [ [Q: 9:19 AM] [A: 9:30 AM]
A:
Audience Question:
Q: Is BMC Patrol supported on VIOS lpars ?[Chuck Leese] [ [Q: 9:15 AM] [A: 9:30 AM]
A: see
Audience Question:
Q: I did a nimadm migration install to 7.1 tl 03 sp04 and the num_cmd_elems are still at 2048 for the fiber channel adapters. i thought this was supposed to only go up to 256?[Nick Pizzillo] [ [Q: 9:19 AM] [A: 9:30 AM]
A: I suspect this is because it was a migration. I am sure that if you tried to set them to that on the client you would get an error message. Even if the client shows 2048 it will be enforcing 256 so you probably should set it to 256 to be consistent.
Q: firmware 780? is this for the midsize p series or only the larger frames?[Nick Pizzillo] [ [Q: 9:32 AM]
A: I think it is for the larger frames but you can check at fixcentral or by going to the FLRT home page and selecting the server and firmware
Audience Question:
Q: mentioned be carfeul to run VIOs within entitled CPU values. Would this matter even if there was plenty of free CPU in the shared processor pool?[Bobby Marsall] [ [Q: 9:29 AM] [A: 9:32 AM]
A: Running above entitlement is a bit less efficient than running within. Also, if the processor pool gets consumed, you may suffer performance issues. Its a balancing act
A: The issue is that the VIO server scales by entitlement not VPs so when you run out of entitlement your performance drops badly – this is particularly the case for the SEAs. There are many articles by Steve Nasypany and others saying it is critical for VIO servers to never run consistently above entitlement. You can check this with VIOS Advisor (now the part command). Also be aware that AMS and SSPs require certain minimum entitlement settings. Also in Alexander Paul’s presentation he shows that entitlement makes a difference to the throughput you can get.
PLUS
AMY APPEL
Questions for Care and Feeding of VIOS
Is there a throughput limit on the virtual Ethernet trunk adapter?
Have a look at this presentation by Alexander Paul – it talks about the benchmarking he has done. It used to be a limit of between 0.5 and 1.5 but I believe more recent firmware, etc levels and newer hardware have increased it. If you are current on hardware and firmware (including adapter firmware) and you have sufficient entitlement at both ends, then you should be able to see higher numbers. It is also affected by the MTU size – with an MTU of 65390 and a perfect configuration he was able to get 19.7 Gbits/sec – however remember that changing MTU size requires that you talk to the network team first.