Duplicate IP issues with Linux and virtual machine cloning.
By: Date: July 10, 2019 Categories: Automation & Administration Tags: ,

TL;DR – Some modern Linux distributions use a newer method of identification which, when combined with DHCP can result in duplicate IP addresses when cloning VMs, even when the VMs have unique MAC addresses. To resolve, do the following ( remove file, run the systemd-machine-id-setup command, reboot): # rm /etc/machine-id # systemd-machine-id-setup # reboot When…

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Benchmarking with Postgres PT1
By: Date: June 28, 2019 Categories: Postgres Tags: , ,

In this example, we use Postgres and the pgbench workload generator to drive some load in a virtual machine.  Assume a Linux virtual machine that has Postgres installed. Specifically using a Bitnami virtual appliance. Once the VM has been started, connect to the console Allow access to postgres port 5432 – which is the postgres…

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Install a bitnami image to Nutanix AHV cluster.
By: Date: June 28, 2019 Categories: Nutanix Tags: , , , ,

One of the nice things about using public cloud is the ability to use pre-canned application virtual appliances created by companies like Bitnami. We can use these same appliance images on Nutanix AHV to easily do a Postgres database benchmark Step 1. Get the bitnami image wget  https://bitnami.com/redirect/to/587231/bitnami-postgresql-11.3-0-r56-linux-debian-9-x86_64.zip Step 2. Unzip the file and convert…

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Nutanix AES: Performance By Example PT2
By: Date: December 18, 2018 Categories: Nutanix Tags: , ,

How to improve large DB read performance by 2X Nutanix AOS 5.10 ships with a feature called Autonomous Extent Store (AES).  AES effectively provides Metadata Locality to complement the existing data locality that has always existed.  For large datasets (e.g. a 10TB database with 20% hot data) we observe a 2X improvement in throughput for random…

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Nutanix AES: Performance By Example.
By: Date: December 17, 2018 Categories: Nutanix Tags: , ,

How to reduce database restore time by 50% During .Next 2018 in London, Nutanix announced performance improvements in the core-datapath said to give up to 2X performance improvements.  Here’s a real-world example of that improvement in practice. I am using X-Ray to simulate a 1TB data restore into an existing database.  Specifically the IO sizes…

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How scalable is my Nutanix cluster really?
By: Date: November 20, 2018 Categories: Nutanix Tags: ,

In a previous post I showed a chart which plots concurrency [X-axis] against throughput (IOPS) on the Y-Axis.  Here is that plot again: Experienced performance chart ogglers will notice the familiar pattern of Littles Law, whereby throughput (X) rises quickly as concurrency (N) is increased.  As we follow the chart to the right, the slope flattens…

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Working with fio “distribution /pereto” parameter
By: Date: November 12, 2018 Categories: Nutanix,X-Ray Tags: ,

The fio Pareto parameter allows us to create a workload, which references a very large dataset, but specify a hotspot for the access pattern.  Here’s an example using the same setup as the ILM experiment, but using a Pareto value of 0:8.  My fio file looks like this.. [global] ioengine=libaio direct=1 time_based norandommap random_distribution=pareto:0.8 The…

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You are here. The art of HCI performance testing
By: Date: November 9, 2018 Categories: Nutanix

At some point potential Hyper-converged infrastructure (HCI) users want to know – “How fast does this thing go?”.  The real question is “how do we measure that?”. The simplest test is to run a single VM, with a single disk and issue a single IO at a time.  We see often see this sort of…

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X-Ray scenario to demonstrate Nutanix ILM behavior.
By: Date: October 25, 2018 Categories: X-Ray Tags: ,

Specifically a customer wanted to see how performance changes (and how quickly) as data moves from HDD to SSD automatically as data is accessed.  The access pattern is 100% random across the entire disk. In a hybrid Flash/HDD system – “cold” data (i.e. data that has not been accessed for a long time) is moved…

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HCI Performance testing made easy (Part 3)
By: Date: September 17, 2018 Categories: X-Ray Tags: , , , , ,

Creating a HCI benchmark to simulate multi-tennent workloads     HCI deployments are typically multi-tennant and often different nodes will support different types of workloads. It is very common to have large resource-hungry databases separated across nodes using anti-affinity rules.  As with traditional storage, applications are writing to a shared storage environment which is necessary to…

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