--- title: "Amir Kolahi (@echoamir) | Hashnode" description: "DevOps. Read the latest articles by Amir Kolahi on Hashnode." url: "https://hashnode.com/@echoamir" --- @echoamir # Amir Kolahi @echoamir · Joined October 2025 DevOps ### [Why Docker Uses pivot\_root (and Not Just chroot)](https://amirkolahi.ir/why-docker-uses-pivot-root-and-not-just-chroot?utm_source=hashnode&utm_medium=feed) When you run docker run alpine sh and type ls /, you see Alpine's files — bin, etc, lib — and nothing from your actual machine. Your home folder, your SSH keys, your /etc/shadow: none of them are ther 8 min read · [amirkolahi.ir](https://amirkolahi.ir/why-docker-uses-pivot-root-and-not-just-chroot?utm_source=hashnode&utm_medium=feed) [1](https://hashnode.com/posts/why-docker-uses-pivot-root-and-not-just-chroot/6ada0a0970561a460423373d) [Oct 22](https://hashnode.com/posts/why-docker-uses-pivot-root-and-not-just-chroot/6ada0a0970561a460423373d) ### [Highly Available Kubernetes Monitoring: Prometheus + VictoriaMetrics](https://amirkolahi.ir/highly-available-kubernetes-monitoring-prometheus-victoriametrics?utm_source=hashnode&utm_medium=feed) A step-by-step guide to building a monitoring stack with no single point of failure, using Prometheus for metric collection and VictoriaMetrics for long-term storage. Table of Contents Why This Arch 13 min read · [amirkolahi.ir](https://amirkolahi.ir/highly-available-kubernetes-monitoring-prometheus-victoriametrics?utm_source=hashnode&utm_medium=feed) [Sep 14](https://hashnode.com/posts/highly-available-kubernetes-monitoring-prometheus-victoriametrics/6aa79b5fb63629f1b82c90e6) ### [Ceph Storage Cluster — From Concepts to a Working Application](https://amirkolahi.ir/ceph-storage-cluster-from-concepts-to-a-working-application?utm_source=hashnode&utm_medium=feed) A complete, hands-on reference covering Ceph architecture, a 3-node cluster deployment with cephadm, object (RGW/S3) and block (RBD) storage, and a containerized application that consumes both. Enviro 21 min read · [amirkolahi.ir](https://amirkolahi.ir/ceph-storage-cluster-from-concepts-to-a-working-application?utm_source=hashnode&utm_medium=feed) [3](https://hashnode.com/posts/ceph-storage-cluster-from-concepts-to-a-working-application/6a465bd4ed0f34e3cac0058c) [Jul 2](https://hashnode.com/posts/ceph-storage-cluster-from-concepts-to-a-working-application/6a465bd4ed0f34e3cac0058c) ### [HashiCorp Vault — Learning Guide](https://amirkolahi.ir/hashicorp-vault-learning-guide?utm_source=hashnode&utm_medium=feed) A hands-on walkthrough of HashiCorp Vault covering secrets management, dynamic database credentials, and Kubernetes authentication. Table of Contents What is Vault? Phase 1 — Running Vault with Doc 13 min read · [amirkolahi.ir](https://amirkolahi.ir/hashicorp-vault-learning-guide?utm_source=hashnode&utm_medium=feed) [Jun 30](https://hashnode.com/posts/hashicorp-vault-learning-guide/6a4393f899104b0352535e99) ### [Installing Kafka Clusters with Helm Charts: A Step-by-Step Guide](https://amirkolahi.ir/installing-kafka-clusters-with-helm-charts-a-step-by-step-guide?utm_source=hashnode&utm_medium=feed) Apache Kafka is the backbone of modern data streaming, and deploying it on Kubernetes ensures scalability and resilience. In this tutorial, we will set up a Kafka cluster in KRaft mode (without Zookeeper) using a custom Helm Chart. By the end of this... 4 min read · [amirkolahi.ir](https://amirkolahi.ir/installing-kafka-clusters-with-helm-charts-a-step-by-step-guide?utm_source=hashnode&utm_medium=feed) [Dec 18, 2025](https://hashnode.com/posts/installing-kafka-clusters-with-helm-charts-a-step-by-step-guide/6943a3c2e506a7f8e9f08d28)