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  • Building a Debian 11 Vagrant Box using Packer and Ansible

    Sometimes it might be necessary to create one’s own Vagrant base box for reasons too numerous to mention here. Let’s assume you want to build a new base box for Debian 11 (bullseye) to run on Virtualbox. Previously I would have run through the installation process followed by customising the VM’s installed packages and installing…

  • Install the Oracle Cloud Infrastructure CLI on Ubuntu 20.04 LTS

    This is a short post on how to install/configure the Oracle Cloud Infrastructure (OCI) Command Line Interface (CLI) on Ubuntu 20.04 LTS. UPDATE 220221: Ubuntu 20.04 LTS is going out of support very soon – you should really use a different LTS release instead of this one! The steps presented in this article should apply…

  • Deploying I/O intensive workloads in the cloud: LVM RAID

    I recently blogged about a potential pitfall when deploying the Oracle database on LVM (Logical Volume Manager) with its default allocation policy. I promised a few more posts detailing how to potentially mitigate the effect of linear allocation in LVM. The post was written with the same Oracle 19.12.0 database deployed to Oracle Linux 8.4…

  • Oracle Cloud Infrastructure: using the CLI to manipulate Network Security Groups

    I frequently need to update security rules in one of my Network Security Groups (NSG). Rather than logging into the console and clicking my way through the user interface to eventually change the rule I decided to give it a go and automate the process using the Oracle Cloud Infrastructure (OCI) Command Line Interface (CLI).…

  • Linux BPFtrace: slightly more advanced use cases involving kprobes

    If you look at some of the examples of how to use bpftrace – more specifically how to enable kprobes – you might wonder how to use the tool in more advanced cases. This article was prompted by my research into why biotop as part of the bcc tools initially reported 0 kb read/written on…

  • Deploying I/O intensive workloads in the cloud: don’t fall for the LVM trap

    I have been assessing the “best” storage option for Oracle databases deployed on Infrastructure as a Service (IaaS) VMs quite a few times now. As part of the discussion DBAs often pose the question whether using Linux’s Logical Volume Manager (LVM) is a good choice for data files. It can be, depending on the circumstances…

  • Do you know perf trace? It’s an almost perfect replacement for strace

    Last night while I was working on my POUG 2021 presentation I looked up what’s new with perf(1) since I last spoke about profiling and tracing Linux on-premises and in the cloud back in 2017. Unsurprisingly, quite a few things have changed. A quick warning before we begin As with every tracer/profiler, using tools such…

  • Do I really have to set resource limits for Oracle in systemd unit files?

    TL;DR: it is very much required to set resource limits in systemd unit files. If you’d like to learn more about potential directives to put into a unit file, please have a look at the earlier post I wrote for a more thorough explanation. I also wrote a short post about a potential unit file…

  • Installing perf on Ubuntu 20.04 LTS in Oracle Cloud Infrastructure

    This is a very short post with instructions on how to install perf on Ubunutu 20.04 LTS in Oracle Cloud Infrastructure (OCI). I created my VM using the Canonical-Ubuntu-20.04-Minimal-2021.06.14-0 image. Updating the image first The first thing I do with each image I spin up in the cloud is to update all the packages. By…

  • Using systemd to start an Oracle single instance database when booting

    I don’t work with systemd frequently enough to remember its syntax and other intricacies so I thought I’d just write down how to start an Oracle 19c single instance database via systemd on Oracle Linux 8.4. Primarily so I can look it up later when I need it, but isn’t that the reason many bloggers…