5 Essential Tips for Maximizing Your Experience at Nutanix .NEXT for Bloggers
You have a nice OVF or an OVA image and you are ready to deploy that virtual appliance to AHV. There is just one more step required. Well, maybe more than one. It is not possible to import OVA and OVF files to AHV. Extraction of the files of the image as well as upload of the VMDK files is required prior to deployment.Please follow instructions provided in KB-3621 AHV: Import OVA and OVF image
If you ever need to present storage to your Guest OS directly via ISCSI here is some useful information for you. To provide access to cluster storage, Volumes utilizes an iSCSI data services IP address to clients for target discovery which simplifies external iSCSI configuration on clients. This iSCSI data services IP address acts as an iSCSI target discovery portal and initial connection point. Nutanix does not recommend configuring iSCSI client sessions to connect directly to Controller VM IP addresses. The data services address is owned by one Controller VM at a time. If the owner Controller VM becomes unavailable, the address moves to another Controller VM, ensuring that it is always available. This IP address is also used as a cluster-wide address by clients configured as part of Nutanix Files and other products. This IP address: Should be in the same subnet as the cluster Controller VM IP eth0 network interface addresses Helps load balance storage requests Enables path optimizati
Similarly to a CVM, Prism Central VM can run out of space.There are three main contributors:localhost_access_log.txt not being rotated properly Nutanix Insights collector log file have consumed more disk space than expected on Prism Central and Controller VMs multiple Nutanix Guest Tool installers are stored in the home directory of Prism CentralWhile the engineering team is working on improving the product behaviour, there are some things you can do about preventing a PC failure:Log in to the PC VM. Navigate to the /home partition List the contents of the directory by size and look for any large unused files that can be deleted.Some common sub-directories under /home where large files are likely to be found. Files in these locations can be deleted to free up space. Delete the files in the folder but NOT the folder itself./home/nutanix/software_downloads/ - Delete any old versions other than the versions you are currently upgrading /home/nutanix/software_uncompressed/ - Delete any ol
In addition to data compression and data deduplication — features that are expected nowadays to be present on any storage aware platform Nutanix AOS also offers Erasure Coding. For workloads with cold data present (no write within past 7 days), when enabled, EC encodes a strip of data blocks on different nodes and calculates parity. In the event of a host and/or disk failure, the parity can be leveraged to calculate any missing data blocks (decoding). In the case of DSF, the data block is an extent group and each data block must be on a different node and belong to a different vDisk. Once parity is computed, the data block copies are removed and replaced with the parity information. Workloads Recommended for Erasure Coding Write once, read many (WORM) workloads. Backups. Archives. File servers. Log servers. Email (depending on usage). Workloads Not Ideal for Erasure Coding Anything write- or overwrite-intensive. VDI. Because of data-avoidance technology like intelligent c
Do you still wonder which one to use Number of vCPU or Number of Cores per Socket when configuring a VM? You read something about it and it makes sense and you think you will now remember only to stumble upon the same dilemma sometime later. Shall we clear this once and for all? vCPU and cores are inherently bound to a NUMA node which, in essence, is as a processor with direct attached memory. Under some (but not all) conditions, accessing memory or devices across NUMA boundaries will result in decreased performance. Hence the goal is to configure a VM with CPU and memory values that remain within the boundaries of a single NUMA node. The exception would be a NUMA-aware application. Another thing to remember is that hot add of the number of cores is not supported on AHV meaning adjustment of number of cores value for a VM requires the VM to be a powered off. To ensure optimal performance of the VMs in the cluster follow simple rules: Use vCPUs instead of cores to increase the
While it is not as a straightforward process as we would like for it to be there is an option to add a NIC to your Move VM. Login to Prism Element Add New NIC to the Nutanix-Move appliance and select the network Launch the console of Nutanix Move appliance. Switch to root user Use vi editor or any other editor of your choice to open the file /etc/network/interfaces Add the second interface eth1 configuration in the format below based on DHCP/Static IP addressing. Restart the networking service.Please Note: If you are using Move 3.0.3 or above you can skip Step-7 and Step-8. That'll be taken care automatically. There will be an existing script named "start-xtract" under "/opt/xtract/bin". Overwrite that script with the one provided in the KB (see link below). Change the permissions for the script. Stop iptables and restart move services. Verify the new eth1 interface configuration using "ifconfig eth1". See KB7399 - Procedure to add a second NIC interface on Move v3.0.2 for detailed ins
The abundance of options causes anxiety. That’s a proven fact. It is only true, however, if those options are hardly distinguishable. This is not the case with Nutanix DR options at all as each feature has a clear purpose and application. It all starts with an SLA. Understanding your disaster scenarios and the amount of data that you are ready to lose in the event of the disaster is the key to choosing a solution that is right for you. Roughly, there are several main options: Local backups (also known as Time Stream). Use these to roll back any Guest OS maintenance that went wrong. Remove a snapshot when the maintenance is over and the rollback is no longer required. Do not leave your snapshots unattended. Remote backup and DR: Asynchronous Replication: Protection from VM Corruption and Deletion as well as from a total site failure. Snapshots can be 1hr or longer apart. Near-sync Replication - leverages Lightweight Snapshots that are snapshots of the metadata. Recovery points can
We have already mentioned some helpful resources relevant to SNMP configuration. This time we will take a look at examples, logs location and connectivity testing. Important:Nutanix appliances support only SNMP v2c and v3 (support for v2c in AOS 5.5 and higher). Starting from AOS version 4.1, auth-type MD5 is no longer supported. With SNMP v2c Nutanix support SNMP TRAP instead of SNMP GETFollow trough to KB-1333 Configuring and Troubleshooting SNMP monitoring for commands and examples.The article also reference two more KB articles as well as SNMP related PowerShell commands:KB-2448 How to import MIB in zenossKB-2028 Integrating Nutanix with Solarwinds
I’m sure you have seen that one before. In most cases you expect it or at least understand what caused it. In some instances you probably ignore it (we all do, no shame). What if this happens when you log into the CVM or the host? Has cluster security been compromised?During the upgrade or rescue of the AOS new keys are created for each node in the cluster. When you open SSH session, these keys are compared to those that were noted on the client previously and since there is a mismatch a warning is triggered.KB-2388 Upgrade/Re-install of AOS changes the ssh key for remote host identification explains how to clean up the keys to get rid of the warnings.
I feel it is time to address a seemingly minor question: should you re-image your nodes when re-using them from an existing cluster? To give a better idea of a setup, think of a cluster with eight nodes, for example. You would like to scale down the cluster and re-use 4 of those nodes to form another cluster. You have evicted the nodes, and you could create a new cluster at this stage but let's take a look at the pros and cons of rushing forward.Cluster creation does no wipe the system. All the files on the nodes remain as they are when you trigger cluster creation. That sometimes can mean issues with LCM upgrades or the cluster creation may error out. To resolve those issues you would need to find those files and chances are you would need a Nutanix Support Engineer to deal with that.Some features introduced in software releases are only available if the version is a fresh installation rather than an upgrade.Any networking changes you might need are easy to apply during the foundation
All Nutanix clusters that run on third-party hypervisors share the same problem – how to communicate to that hypervisor.A Controller VM performs an array of tasks, many of which are triggered by the state of the host. In addition to that, a range of health checks is running regularly to ensure the cluster's health. For ESXi, CVM collects the information via SSH. Turning off SSH service on a host results in a multitude of health errors.While recommendation exists to keep the SSH service down on the ESXi hosts and only bring it up for ad-hoc tasks, this is not the way with Nutanix. Instead, look at strengthening network security. Consider limiting access to the hosts via SSH form a limited number of network segments, that are well protected by multiple additional layers of firewalls, two-factor authentication and what not.Stay safe, stay secure.KB-2051 NCC Health Check: esx_check_servicesvSphere Administration Guide for Acropolis: Nonconfigurable ESXi Components
Any modern environments consist of multiple layers each of which contains multiple components. There are switches and routers, firewalls, physical server, application servers, applications themselves and, of course, users. Each of the components has logs of more than one kind, location and severity. All the components interact with each other directly or indirectly. I am certain you have found yourself in a situation where to establish a root cause you had to inspect logs of more than one entity. Establishing a timeline of events is always easier when the sources of the events’ clocks are synchronised and are located in one central location. While the clocks are handled by the NTP the centralised logs location is a syslog server or in this case a remote syslog server implying that it is separate to the origination of the logs. In addition to the benefits already mentioned, remote syslog server allows to access logs for the systems that are already dead, decommissioned or replaced. Nuta
When you see an alert about one of the NICs being down the first thought is “oh-oh!”. There is more than one NIC in the host and the traffic will switch over to the other interface or the bandwidth is now reduced (when LACP is enabled, for example). If the environment is not running at the brink of its capacity then a loss of one of the network interfaces should not cause an immediate impact. The issue is detected by NCC health check nic_link_down_check which runs every hour and generates the alert if any issues are found. In the majority of cases using networking troubleshooting logic is enough (make sure the interface is physically connected, devices on both ends are configured correctly and are functioning properly).In some cases, however, the alert may be a false positive. If an interface used to be connected or, in some instances, after cluster expansion on a new node. Eliminate the possibility of the alert being true first. Verify physical connectivity of the host to the switch.
PCI device enumeration is one of a large number of concepts that transitioned from the physical world. Originally, being a bus and a slot number now, of course, is a virtualised concept.When OS boots during the POST process the local devices are enumerated (checked for presence and size). If an expected device is found at the PCI slot that is a failure of the test. In AHV deployments, the Controller VM (CVM) runs as a VM and disks are presented using PCI passthrough. That means that if AHV PCI devices enumeration has changed CVM may not be aware of the fact and attempt to direct I/O to the devices that are no longer accessible via known PCI bus and slot. This can happen after hardware replacement on an AHV host and the CVM will not boot or will boot with only part of the expected devices accessible. Compare PCI slot numbers of SCSI controllers on AHV host and the CVM and update the enumeration of the devices on the CVM. For more details look at KB-7154 AHV | CVM might not boot after ha
SFP give us freedom of choice and granular control over the media being used in the network segment. Mix and match optic fibre and copper of various throughputs and lengths of the segment. Very convenient and flexible solution and easily replaceable SFP modules. When troubleshooting issues or during maintenance, the hardware details of the SFP module plugged into a host NIC may need to be identified and verified. Typically the useful information is printed on the SFP label but who has the time for this. More importantly, it would mean taking the SFP module out and that means another maintenance window. Using ethtool on AHV and XenServer will help with retrieving information like vendor, model, part number, serial number, transceiver type, cable length, connector type, signal quality, and more. For more details refer to KB-9102 How to identify plugged-in SFP module model, manufacturer, and hardware details
If you ever find yourself in a position of locking root user on an ESXi host, there is an easy way out.Since the CVM communicates to the local host via a dedicated network handled by vSwitchNutanix it is possible to clear the lock for the ESXi host from the CVM. Verify first that the account is locked. Typically, authentication via an SSH session fails while the DCUI accepts the credentials. Log in to a CVM and call for the account lock rest remotely while connecting to the internal IP of the host. For more details on the verification and the process itself, refer to KB-5703 ESXi root password does not work via SSH, but works via DCUI.For an overview of networking vSphere Administration Guide for Acropolis (using HTML 5 Client) AOS 5.18: Networking Components.
Ubuntu Cloud Images are pre-installed disk images that are customized by Ubuntu engineering to provide Ubuntu Certified Images, Openstack, LXD, and other features in public cloud environments.Due to the pre-built image and customization the OS requires specific virtual hardware such as a serial port that AHV does not include by default. When trying to boot a VM on AHV from any of the Ubuntu Cloud images, the boot process stalls after loading the Btrfs module as the hardware is not there.This can be helped by customizing the VM manually using a combination of Prism and aCLI commands or by leveraging API calls.Download Ubuntu cloud image in .img format Upload as Disk to Prism Image Services Create a new VM and attach the disk created in step 2 as Type: "Disk", Operation: "Clone from Image Service", Bus: "SCSI" and for Image select the name of the uploaded image and then click "Add" Select "Custom Script" at bottom of the window (AOS 5.10.6 and later) and in "Type Or Paste Script" paste t
We’re over a hump day, and I would like to share an insight that may come handy to those of you that upload binaries to their clusters manually. Did you know that you have seven days to use the upgrade package that you uploaded to the cluster manually before it is removed from the file system? That’s right. Even if you have triggered pre-upgrade checks for the version, but the package is not used it deleted automatically. Make sure to clean up uncompressed software location and check the /home space on a CVM before you re-attempt the upload.KB-10300 Uploaded AOS upgrade binary is unavailable on Prism has more information To wrap your head around upgradesAll things considered — upgrade sequence and preaparation guidelinesFoundation of a successful upgrade - up to date FoundationNutanix upgrades FAQ: AOS, LCM, NCC, Hypervisors, Files
To reboot an ESXi host, to trigger a PPR for a DIMM for example, when DRS is on and fully automated there a few questions to be answered before putting together a sequence of steps.First of, should we disable the DRS? When a host is taken out of the maintenance mode the DRS will rebalance the load on the host and as such VMs will migrated back onto the host that has just exited maintenance. What if the CVM is not ready? After all, the CVM is the entity the serves storage to the VMs. Will be VMs affected if the CVM is not fully booted or has not exited maintenance mode by the time VMs are returned to the host? Luckily, the VMs will not be imacted in any way as at the time of placing CVM into the maintenance mode the storage traffic is re-routed and is now handled by other CVMs in the cluster.Should we evacuate powered off VMs for a host reboot? The answer depends on the risk tolerance and risk assessment of the issue. Is it likely that the host may experience issues after a reboot? If s
Since Esperanto never really took off English has become the universal language for business, education and IT industry.It does not mean, however, that you must use English in your environment. Prism supports localization to Japanese and Chinese languages. As any feature Prism localization has its limitations:Logical entities that do not have a contextual translation available in localized language are not localized. The AOS generated alerts and events are not localized to the selected locale language. Following strings are not localized: VM, CPU, vCPU, Language Settings, licensing details page, hardware names, storage denominations (GB, TB), About Nutanix page, EULA, service names (SNMP, SMTP), hypervisor types.To change the language setting, follow the Prism Web Console Guide: Localization.If there is an issue with changing the language for the Prism configured with Active Directory see if KB-10166 Language setting cannot be changed in Prism if logged in as Domain Administrator appli
We know you care about your infrastructure. Every time and auto support ticket is created for one of Nutanix clusters a Support Engineer contacts the person who is assigned as Support Contact for the asset. You can spread the load within your team, assign the contact based on the time zone the asset is within or use any other method you like. The choice is yours!Help us to choose the right person to work with, shorten the resolution time and avoid the avoidable – configure Support Contact for your Nutanix clusters.Log in to my.nutanix.com. Click Support Portal. Under Products, click Installed Base. Click Assets tab. Select all assets by clicking on the checkbox located at the top left of the table. Click Edit Assets. Update the details and click on the green tick box located at the bottom right of the dialogue box. Click Clusters tab. Select all clusters by clicking on the checkbox located at the top left of the table. Click Edit Clusters. Update the details and click on the green tick
Are you new to Era and want to learn more about it? Are you an experienced engineer working with the product looking for answers?Era is a database as a service (DBaaS) that automates and simplifies database administration, bringing one-click simplicity and invisible operations to database provisioning and life-cycle management. Nutanix has an article with over 50 questions answered about Nutanix Era 2.0. The article covers questions on the variety of topics, such as:Time Machines Profiles Provisioning and Cloning Across Multiple CLusters SAP HANA on Era Copy Data Management for Multiple Databases SQL Server Patching SQL Server Database Group PostgreSQL Patching Oracle Restore PostgreSQL RestoreSome of the questions answered are:Can a single Era management plane handle multiple Nutanix clusters?What type of networks are supported for Era Agents?Can two or more pre-2.0 Era instances be converged into one?What version of Oracle is supported for Oracle Restore?Can we clone a few databases
Flow Security Central (FSC) is a SaaS product that detects and analyses security vulnerabilities in near real-time across multiple cloud environments. FSC supports the following capabilities.Visibility into Security Compliance: FSC provides businesses with a security heat map and complete visibility into the security posture of their environment using more than 800 automated audit checks based on the industry's best practices. Optimization of Security Compliance: FSC provides cloud operators with a one-click feature to easily fix their security issues. FSC also provides out-of-the-box security policies to automate the checks for common regulatory compliance policies, such as HIPAA, PCI-DSS, CIS, and so on. Control over Security Compliance: FSC helps you to set policies that continuously detect security vulnerabilities in real-time and automate the actions needed to fix them. You can also create your custom audit checks in FSC to meet your business-specific security compliance needs. Fo
When it comes to passwords, I am the worst. I can not remember a single password I have. Worse, I struggle to type it correctly. In some way, this is an advantage as I have to reset all my passwords frequently. While you, reader, may think that this does not apply to you, I am confident I am not alone in my struggle. Incidentally, I have seen a few cases dedicated to being unable to log in to Prism with admin credentials or to a CVM as nutanix. Below is a very generic approach on how to handle the issue.First of all, I feel compelled to remind you that there is a lock out timeout for consecutive failed authentications. By default, the timeout is 15 minutes, but you can unlock the account from a CVM when logged as nutanix.In some cases, a password is simply unknown for whatever reason. Again, if you know nutanix user credentials, you can log in to CVM and change the password.What if you are certain that the password is correct and, maybe, even unlocked it already but the Prism still doe
If you have decommissioned a vCenter without unregistering it with the Prism and now are unable to complete the task, there may be a solution.For AOS 5.5.x provided the symptoms match an upgrade may be required to resolve the issue. If you see all of the following, upgrade to AOS to 5.5.6, 5.8.2, 5.9 or later.An attempt to unregister a vCenter instance that does not exist anymore from Prism using vCenter Registration page creates a task that fails at 100% progress. Using the "ncli managementserver unregister" command produces the same outcome. Uhura logs (home/nutanix/data/logs/uhura.out) show vCenter is not reachable and is not able to delete the connection object.Nothing is fully predictable - we understand that. Some things still can be planned. We encourage you to plan the maintenance, especially when it comes to decommissioning of the components. It is generally more difficult to solve the problem where a component no longer exists then while it was still available.For more detail
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