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Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

This topic is a chance to clarify your questions about Cisco HyperFlex installation, upgrading and troubleshooting best practices. During the session Cisco experts will answer questions about how to upgrade, install and troubleshoot common issues on Cisco HyperFlex, including cluster Expand Problem.

Questions related to general issues seen in the HyperFlex environment are also welcome and encouraged.

To participate in this event, please use the Join the Discussion : Cisco Ask the Expertbutton below to ask your questions

Ask questions from Monday 13th to Friday 24th of January, 2020

Featured experts
AfrojAfroj Ahmad is an Escalation Engineer on the CX-HTEC Server Virtualization Team. He has thirteen years of experience working with large enterprise and service provider networks. Afroj specializes in Data center and Network Management solution, including; Cisco HyperFlex, UCS-B and C series, Cisco Nexus 5000, Nexus 3000, Nexus 2000, Nexus 1000, Nexus 9000, MDS, SNMP, LMS and Prime Infrastructure. He holds a master’s degree in computer application. Afroj holds the CCDP, VCP 6 (VMware Certified Professional), CCNP R&S, Cisco Certified Hyperflex systems Engineer, ITTL v3, SCJP (Sun Certified Java Professional) and a CCIE DC certification (#49873).

AasimAasim Mohamed is a Technical Consulting engineer on the Server Virtualization and Storage team. He has ten years of experience working with Data Center Technologies. Aasim specializes in UCS-B and C - series servers, UCS-FI, HX, Nexus 2000 and 5000, MDS, VMware vSphere 5.5 to 6.7 suite - Installation, Configuration and Troubleshooting-, HPE servers / ML, DL and Blade line products. Aasim holds a degree in Engineering and Electronics. He holds the Cisco Hyperflex for system engineers and VCP (VMware Certified Professional) certifications.

Afroj & Aasim might not be able to answer each question due to the volume expected during this event. Remember that you can continue the conversation on the Data Center community.

**Helpful votes Encourage Participation! **
Please be sure to rate the Answers to Questions

30 REPLIES 30
Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

 
Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Does Cisco HyperFlex use vSAN?

Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Hi Singh,

 

Your question is too open-ended.

 

Just for the Hyperflex cluster configuration, we dont need vSANs to be configured on UCS or Upstream switch (Nexus or MDS).

 

However you can present FCoE luns to HX cluster's ESXi host for which vSAN can be configured and have to update SP associated with the HX servers. Just as you do for other non-HX servers.

 

Here is a reference for UCSM configuration:

https://www.cisco.com/c/en/us/td/docs/hyperconverged_systems/HyperFlex_HX_DataPlatformSoftware/Network_External_Storage_Management_Guide/b_HyperFlex_Systems_Network_and_External_Storage_Management_Guide_3_0/b_HyperFlex_Systems_Network_and_External_St...

 

 

Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Hi Arsh,

VMware VSAN and Hyperflex works little different.

 

Cisco Hyperflex offers both hybrid and all-flash options just like vSAN, however, the scalability is limited to eight storage nodes in a hybrid configuration and 16 in an all-flash configuration. vSAN on the other hand scales to 64 nodes

 

These are good readouts #

https://www.trustradius.com/compare-products/cisco-hyperflex-vs-vmware-vsan

Top 5 Reasons to Choose Cisco HyperFlex Systems:

https://www.cisco.com/c/dam/en/us/products/collateral/hyperconverged-infrastructure/hyperflex-hx-series/le-wp-hxt-op.pdf

 

Hope this will help !!

Thanks- Afroz [Do rate the useful post] ****Ratings Encourages Contributors ****
Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

we would like to add an additional pair of vNICs to our Cisco Hyperflex hosts. The Cisco HX Data Platform Installer wizard did not seem to provide any options for adding additional vNICs to the hosts and we would like to know if doing so manually is likely to cause difficulties with any future upgrades or general operation of the platform.

Highlighted
Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Hi Tarun,

 

Thanks for your interest !

Yes, You can safely add additional vNICs to HX nodes with limitation that you keep existing configuration of “core” networking untoched i.e. you will not delete/change mgmt and data vSwitches and/or move theirs ports to other vSwitch. I recommend to keep vmotion vNICs configuration as is, too.

 

If you require additional management interface on ESXi side, you can bind it to newly created pair, too. However, keep in mind than number of vmkernel adpaters are limited. I also recommend to check existing vSwitches configuration for physical NICs active/standby configuration. The recommendation is to setup same A/S policy across all nodes to both close the traffic within a single FI and load balance it across Fis.

 

Thanks- Afroz [Do rate the useful post] ****Ratings Encourages Contributors ****
Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

In our HX environment, on Vcenter we are seeing controller VMs have "Virtual machine Memory Usage" alarms in critical state. 

Can you please let me know why i am getting these alarms and how i can limit the memory usage to avoid such alarms in future. 

 

Thanks in advance!

Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

HI Suraj,

 

Please check the below things:

# Checked Controller VMs (CVM) are at 72 GB memory ?
# Confirmed there is enough free memory on controller VM

Share the output of "free" from SCVM

Thanks- Afroz [Do rate the useful post] ****Ratings Encourages Contributors ****
Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

# Checked Controller VMs (CVM) are at 72 GB memory. yes it is 78GB


below is the output@
root@SpringpathController:~# free
           total           used             free             shared     buff/cache available
Mem: 74234748  42211016    29987484   6912      2036248     31464156
Swap: 0 0 0

Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

thanks for your reply, It sounds like you are hitting known VMware issue that is being tracked under these defects#
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvf12501/?reffering_site=dumpcr
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvf87493

The workaround for this issue is to disable the virtual machine memory usage alarm to avoid false positives as mentioned by Aasim in one of his  response.


To disable the alarm definition:
Select the vCenter object in the navigation pane of the vSphere Web Client
Click the "Monitor" tab, then the "Issues" sub-tab
Here, select "Alarm Definitions" and search for "Virtual machine memory usage"
Highlight the alarm and click "Edit", then un-check "Enable this alarm"
Click "Finish"

For reference, See VMware article: https://recommender.vmware.com/solution/SOL-12357

Thanks- Afroz [Do rate the useful post] ****Ratings Encourages Contributors ****
Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Thanks for the reply Afroj!

I have another question : Can we remove and add the same converged node back in the same cluster?

If not, what is the reason and what would be the workaround to add the same node back in the cluster ?

 

Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Hi Suraj,

 

More than happy to help you.

 

Can we remove and add the same converged node back in the same cluster? No


Yes you cannot add the same converged node back in the cluster.Zk maintains the mapping of the disk UUIDs to the pNode ids. So if you remove the a node and then want to add it back with a redeployed SCVM that changes the pNode id. Now zk will have to map node same disk uuids with the new pnode id which creates an issue. so  it is not possible

 

Only way I see if you  replace all the disk :(  

 

 

 

Thanks- Afroz [Do rate the useful post] ****Ratings Encourages Contributors ****
Cisco Employee

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Hello Suraj,

 

Thank you for your interest.

 

It is quite normal for Controller VM (SCVM) memory utilization to go high as the Storage controller is a pass-thru device , all IOs are handled by SCVM.

 

Therefore you may see Critical alerts in vCenter about high memory utilization for the SCVMs again and again.

 

It would be best to suppress this alarm from vCenter or simply ignore.

https://docs.vmware.com/en/VMware-vSphere/6.0/com.vmware.vsphere.hostclient.doc/GUID-85A83C37-BE5B-4A35-804F-901063CECFAB.html

 

Also as mentioned in above reply, try the command from SCVM SSH:- 

#free -m

# vsphere client -> VM edit settings -> Memory Allocated

 

Thanks,

 

Aasim Mohammed

 

 

 

Beginner

Re: Ask Me Anything- Cisco HyperFlex: Installation, Upgrade and Troubleshooting

Does Cisco HyperFlex support Hyper V ; are there any challenges ?

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