Host Advanced Configuration

No Image

IBM DS 3500 with vSphere 5.0.x SATP Rules

March 15, 2015 Shady ElMalatawey 0

Few days ago, I went to a customer that has old Virtual Environment. He has 3 hosts IBM SystemX servers, IBM DS3524 SAS Storage which is directly SAS-attached to the hosts and vSphere 5.0 U2. His environment has strange issue: every few minutes, Storage Manager throws an error that “LUN x is owned by not-preferred Controller. Preferred Controllers is Controller A”. He first thought that it was a firmware issue in the DS3524 storage and he asked IBM guys to upgrade the storage firmware. They upgraded the firmware to version 7.86.49 and the problem was still there. First, I checked compatibility matrix of both VMware and IBM and I was shocked that they were different as the following screenshots: VMware one […]

No Image

ESXi Tardisks, Ramdisks & ESXi Local State

January 20, 2015 Shady ElMalatawey 0

Hi All.. During my study for my VCAP-DCD, I came to an interesting point that I’d like to share with you. During reading vSphere Design Sybex V2 by Scott Lowe and Forbies Guthrie, they came though ESXi boot disk partitions and how the boot image is loaded into memory during boot. Long story short, ESXi base image essentially is a compressed file. When booting ESXi image, that compressed file is uncompressed into the memory producing two types of files: VMkernel Executives and Archive Files. VMkernel Executives are .gz files that aren’t shown in the list of file system files and they form the main files system. Archive files, aka. VIBs or VMware Installation Bundles (Anyone experienced with Auto Deploy knows them), contain all […]

No Image

Swap to Host Cache (wrongly aka. Swap to SSD)

January 18, 2015 Shady ElMalatawey 2

Hi All … vSphere 5.0 and later came with so many enhancement for Virtual Infrastructure and Swap to Host Cache is one of these. This feature allows you to use any SSD datastore -some or all of it- as Write-back Cache to swap to it ESXi memory pages in case of Hard State memory contention. Many of vExperts wrote about it and its technical how-to configuration, like Duncan Epping in his complete-guide blog post here. Now, you’re asking: “So, why do you write this blog post?? Do you wanna to copy-paste??!”  The answer is unfortunately, NO!! I write this blog post to answer a question that may come to your mind while reading about this awesome feature: “What is the […]