Deployment Success

What is Erasure Coding? Erasure coding increases the usable capacity on a cluster. Instead of replicating data, erasure coding uses a parity information to rebuild data in the event of a disk failure. The capacity savings of erasure coding is in addition to deduplication and compression savings.   If you have configured redundancy factor 2, two data copies are maintained. For example, consider a 6-node cluster with 4 data blocks (a b c d). In this example, we start with 4 data blocks (a b c d) configured with redundancy factor 2. In the following image, the white text represents the data blocks and the green text represents the copies.   Data copies before Erasure Coding  Computing Parity   Data copies after Computation of Parity  Erasure Coding Best Practices and Requirements: A cluster must have at least four nodes populated with each storage tier (SSD/HDD) represented to enable erasure coding. Avoid strips greater than (4, 1) because capacity savings provide diminishing returns and

I am looking for other customers who have used the witness feature. We have three buildings each about 1 mile from each other. 10g fiber between them. We have two Nutanix clusters, one in each of two of the buildings. We have the ultimate licensing and are already using Metro clustering. I have the fail over set to manual. Today I setup a witness server in the third building. As far as I can tell everything is working. The real question is should I use it? Is anyone using the witness. Does it cause more problems than it solves. At least with manual I have full control when a fail over happens. So far it has been easier to fix my issues than to fail over and almost all issues are network related not nutanix.

What is Metro Availability? Nutanix provides native “stretch clustering” capabilities which allow for a compute and storage cluster to span multiple physical sites.  In these deployments, the compute cluster spans two locations and has access to a shared pool of storage. The solution is currently available for ESXi only.    This expands the VM HA domain from a single site to between two sites providing a near 0 RTO and a RPO of 0. In this deployment, each site has its own Nutanix cluster, however the containers are “stretched” by synchronously replicating to the remote site before acknowledging writes. The following figure shows high-level architecture of a Nutanix Metro Availability deployment:   The following figure shows an example link failure:   Nutanix Metro Availability also can be set up with Async-DR replication to a third site to combine the multi-site resiliency of the Metro setup with traditional space-efficient incremental snapshot backups. Metro Availability Configuration

This alert is generated when an API comes in which is authenticated as "admin". Nutanix recommends any script or third party application sending APIs to the cluster should use a service account rather than using 'admin'. You can read more about this alert from the article "Alert - ExternalClientAccessCheck" If you are seeing this alert, it is informing you that some system is authenticating as admin. To aid in investigation the IP address is provided. The intent is that any 3rd party application or script should be using a service account and not ‘admin’ as this makes command auditing much more reasonable and helps keep the admin password secure. When a third party application such as Veeam is set up to authenticate to the cluster as ‘admin’ that should generate this alert. If you log in to Prism Element as admin, access the REST API explorer, and then test an API you should see this alert because that’s your desktop sending an API as ‘admin’. Likewise if you set up a PowerShell script

We are planning our AHV migration and would like to migrate about 75% of our VM’s (~400) during their negotiated patch outage windows to minimize how many app teams get to set our schedule for us.  Most of these outage windows are in the 3AM time frame. We would like to find an automated/scripted way to do the cutover so that we can set a job to run that script overnight during that window.  I’ve seen some REST calls that look like they could do it.  Has anyone actually done it?  If so, would they mind sharing a sanitized snippet of their Powershell/REST code? Thanks in advance!

In some scenarios, you may need to move a disk from IDE to SCSI bus or vice versa. Sample scenarios include but are not limited to:   VM does not boot due to missing SCSI driver. In such cases, the disk can be converted to IDE to install the missing drivers and then moved back to SCSI. A wrong disk type was used during VM creation. Application requirements dictate the particular type of the disk. You have recently migrated VMs to AHV and noticed that some of the disks appear in IDE format.   After following the disks conversion process from IDE to SCSI (as described in step 2 of the uvm_ide_disk_check) the following doubts arise:   Question: Once the disk gets converted, does it immediately redirect all I/O to the SCSI drive and leave the IDE disk unused? Answer: Once the conversion is completed (which is actually a cloning process from the original IDE disk), the new SCSI disk needs to be attached to the SCSI bus and then the old IDE disk could be removed.    Question: What ar

What is cloud connect? Building upon the native DR / replication capabilities of DSF , the cloud connect feature enables you to back up and restore copies of virtual machines and files to and from an on-premise cluster and a Nutanix Controller VM located on the Amazon Web Service (AWS) or Microsoft Azure cloud.   The following figure shows a logical representation of a “remote site” used for Cloud Connect: Cost and management Amazon or Azure customers are charged only for capacity that is used (not charged for the full capacity). Once configured through the web console, the remote site cluster is managed and monitored through the Data Protection dashboard like any other remote site you have created and configured   About AWS & Azure Storage: Amazon S3 is used to store data (extents) and Amazon Elastic Block Store (EBS) is used to store metadata. When the AWS Remote feature replicates a snapshot data to AWS, the Nutanix Controller VM on AWS creates a bucket on S3 storage. The buck

NVIDIA GRID boards allow GPU virtualization, enabling multiple users to share a single graphics card. GPU virtualization not only provides the benefit of higher user densities, but also delivers native-like performance while accessing a virtual desktop. In 2016, the Pascal-based P series was released—the P100, P4, P40, and P6. The P4 and P6 are best for blade server form factors and the P100 and the P40 are suitable for the other form factors, such as rack mount. Nutanix offers the P100 and P40 in our different hardware choices. In 2018, NVIDIA introduced the Turing Tensor Core–based T4 for cloud workloads, including high-performance computing, deep learning and inference, machine learning, data analytics, and graphics. One of the common causes of being unable to allocate vGPU to guests is caused by the GPU being set to Compute Mode which results in the errors below: The vGPU option may appear greyed out and unavailable When trying to install the NVIDIA-vGPU rpm package from the CVM

You may be familiar with using Nutanix Move to migrate VMs into an AHV cluster, or you may have imported VMs to AHV manually following this method, but what if you want to take your VM out of your AHV cluster to use in a non-Nutanix ESXi cluster, or to deploy on Hyper-V or KVM? Note I said non-Nutanix ESXi cluster. If you have a Nutanix ESXi cluster and an AHV cluster it’s much easier to use Async DR migration since this kind of cross hypervisor DR migration is fully supported from Prism. If you need to export your VM from AHV to another hypervisor there is a documented procedure provided. Here we will be using the articles “AHV | How to access VM disk files on Nutanix container” and “AHV | How to migrate user VMs from AHV to Hyper-V/VMware ESXi/KVM”. The first article covers reviewing your VM configuration from ACLI to identify the VM disks which are named by their UUID, and then how to collect those files using the SFTP protocol on port 2222. The second article describes using th

Hi team, i have questions about capacity calculator let say i have config for 3 node like the picture below,  so in prism will show me 17TB logical capacity correct?  and i have concern in extent store RF2 and N+1 (11TB) in sizer tool, what happen if i have data 15TB which is bigger than RF2 and N+1 size (11TB)?

We are running a nutanix cluster with Hyper-v. this was the worst thing we could do when we started with nutanix. We know that now. But my main question is, is there a way of getting this cluster converted to AHV?   It's a Dell XC cluster with 2 blocks and 5 nodes.   regards

New to Nutanix and have a question that may have already been answered, although I could not find it with a quick search.  We are needing to install an instance of Prism Central in our backup datacenter and need to know if there are any issues in running this application in multiple locations at the same time, or is there a specific installation method for HA?  If HA is not available are there any issues in actively using both instances via round robin DNS entries? Thanks in advance for your assistance. Joe

I am having an External NTP server, Which is tagged to my CVM, unfortunately my AHV is not corresponding with mt NTP server even it is reachable from my hypervisor level. I have checked my Hypervisor thru ssh and run the command ‘date’ its gives me different time from my NTP server.

Hello, I'm not sure if this is the best place to ask this, but I'm not sure where else to ask. I keep getting a message that there's an NGT Update Available on just one of our servers running Ubuntu. I ran an update and it went from 1.1.2 to 1.5.2. After resolving/acknowledging the issue it reported the same message again the next day. Is 1.5.2 not the latest?

What is Jumbo frames?  In computer networking, jumbo frames are Ethernet frames with more than 1500 bytes of payload, the limit set by the IEEE 802.3 standard. Jumbo frames can carry up to 9000 bytes of payload.   When should jumbo frames be used?  Use jumbo frames only when you have a dedicated network or VLAN, and you can configure an MTU of 9000 on all equipment to increase performance. A good general example of this approach is a separate SAN or storage network.   How to check your current MTU status? Run this command on one of your CVMs “NCC Health Check: cvm_mtu_check”. The command checks: On Hyper-V, validates if the MTU size is properly defined for eth0 and eth1 on the Controller VM On AHV, ESXi and Hyper-V, ensures the CVMs can communicate via eth0 with their configured MTU without upstream network fragmentation. For more information about this check, take a look at this article. How to Change AHV Host MTU for Jumbo Frames?  Check out this KB that explains the preparation and

Is Windows Server Failover Cluster supported with shared vmdk with esx? Or only Nutanix Volumes with iscsi? Hypervisor is esx.

Below are new knowledge base articles published on the week of March 8-14, 2020. KB 7424 - NCC Health Check: metro_invalid_break_replication_timeout_check KB 9000 - NCC reports LSI firmware is blacklisted for DELL XC nodes, when LCM inventory does not have any newer versions KB 9042 - Prism Central session times out unexpectedly when a user logged in with 'Admin' role. KB 9063 - [Karbon] Kube DaemonSet Rollout Stuck Alert; Daemonset wrongly reports unavailable pods KB 9068 - AHV | nutanix-network-crashcart scripts fail with "No module named fc_progress" error on hosts imaged with Foundation 4.5.2 KB 9074 - [Karbon] Kubernetes Upgrade Fails with Error: Upgrade failed in component Monitoring Stack Could not upgrade k8s and/or addons Note: You may need to log in to the Support Portal to view some of these articles.

Below are new knowledge base articles published on the week of March 1-7, 2020. KB 8869 - NGT installation via Prism Central on Windows Server 2016 or more recent Operating Systems fails with INTERNAL ERROR message KB 8905 - How to download images from Prism Element clusters via command line KB 8917 - NCC - ERR : The plugin timed out KB 8993 - Foundation : Upgrade foundation using LCM Dark site bundle KB 8997 - Not able to delete a Role in Prism Central KB 8998 - Era Registration fails if container is not mounted on all hosts KB 9004 - Increased number of connections to File Server once migrated from Windows to Nutanix Files KB 9013 - How to Create a Shared Folder in Windows Server 2016/Windows 10 KB 9016 - Unable to open Java console after BMC upgrade from version 7.00 to 7.05 KB 9028 - ERA-DB provisioned from the OOB template failed to register with ERA server KB 9031 - Prism and Microsoft LDAP Channel Binding and Signing KB 9045 - How to find a VM creation date and time in Prism Cen

Let's say that you have utilized the maximum recommended storage space in your cluster, you have an empty slot for another drive and you want to fill it to expand the storage capacity.   There are different types of drives out there, each of our platforms has it's own specifications and requirements.    To check which drives are compatible with your platform, choose your platform on this page and check out the data drives supported.    Your node will be in one of the following configurations:   1) Hybrid: A mix of SSDs and HDDs.  2) All Flash: can accept only SSDs and can contain only an even number of drives.  3) SSD with NVMe: only certain drives slots can contain NVMe, check the system specification via the link above for more information.   When adding more than one drive to a node, allow at least one minute between adding each of the drives. Check out my colleague Jon Kohler’s reply here where he provided some good caveats for adding drives. Specifically, increasing the hot tier c

Hello, I have a cluster up and running for almost a year now without any particular issues. I haven't logged into Prism for a long time and did so recent, and saw an alert on hat the cluster is not able to check NTP. I have them set for North American NTP servers. I think the real problem may be with Zeus, however, as when I SSH into one of the CVMs and almost any command (bur speciifally 'allssh root@192.168.5.1 date') I get: ================== error: ================= ================== Zeus ================= ================== configuration ================= ================== cache ================= ================== is ================= ================== not ================= ================== created; ================= ================== try ================= ================== again ================= ================== later ================= It is the same with any other command I try to run. Your insight is greatly appreciated.

Suppose you need more disk capacity on a virtual machine in your environment. You choose the VM in Prism, click ‘update’, select to edit the appropriate disk, and change the size of the disk from 200 to 300GiB. You click update and see that the task completes successfully, then close the VM update UI. The VM details reflect the increase in disk space, but when you access the VM it appears the capacity of the drive is unchanged! This is actually expected. There is just a bit more work to be done. The partition will need to be extended following the steps for your VM guest operating system. You can see the steps to complete this in Windows from the KB article “Expand volume group disk size on Windows OS” or if you are using Linux, check the KB article “Increase disk size on Linux UVM” 

Let’s say you received an alert stating that all CVMs are not in the same timezone or all hosts are not in the same timezone.   What does it mean? Well, as simple as the alert indicates, the CVMs/hosts are not in the same timezone. We need to ensure that the same timezone is configured across all the CVMs/Hosts as it ensures that all the guest VMs log messages are timestamped consistently.   How will you know about the timezone issue? There is an NCC health check, “same_timezone_check” in place to inform any discrepancy in the timezones.   To know more about the alerts and errors which can be seen and how to change the timezone, take a look at https://support-portal.nutanix.com/#/page/kbs/details?targetId=kA0600000008hm9CAA   Have any questions? Leave a comment and let’s start a discussion.

How do we browse Nutanix containers from command line to check what is contained in it.

Hi I have confuse about the output of the AHV network command "mange_ovs show_interfaces", In the result, I can check the link status and speed of the NICs. But what is the meaning of mode ? I attached a snapshot as the following that give the output of a node in AHV which have 10Gb and 25Gb nic cards, but the mode all display 10000. What is the meaning of mode?

Hello guys, Can anyone please help with NCC Health Check report on Email? The purpose is to receive NCC Health Check every week on Tuesday at 7.00 AM CET. I configured NCC report frequency via Nutanix Prism Central on each nutanix cluster But now I receive a report each Tuesday and Wednesday at 7.00 AM CET. I have tried a method to disable NCC frequency and setup it newly, but no results, no changes. For configuring I used guide - https://portal.nutanix.com/#/page/docs/details?targetId=Web-Console-Guide-Prism-v55:wc-ncc-frequency-configuration-t.html Thank you in advance