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Set RDMs to Perennially Reserved for all hosts under a vCenter server

In most production environments business as usual activities, user errors or business critical changes can sometime make environment deviate from best practices. One such best practice for vSpehre environment is to have RDM devices used by MS cluster set as Perennially Reserved. This blog provides you a quick way to fix the deviations from this best practice. Script Flow: Step 1: Prepare a list of Naa IDs that are used as RDMs in the setup. There are plenty of blogs and community links that cover this part. Below are a few

The output of each method is different but all of them give you the NAA ID for the RDM device. Step 2: Format the list of Naa IDs for use with this script. This script expects the input file format as ...

July 8, 2020 / Akshay / PowerCLI, PowerShell, The Tech Center, vSphere

Network captures in 15-minute batches on an ESXi

You may have reviewed my blog post about Isolation of Intermittent Network Issue. That blog makes you aware, that ESXI comes with a neat utility that can help you capture network traffic at various points within the host. Like most troubleshooting tools, pktcap-uw needs a user to be in front of the system to start the data collection. This is not only operational but also a human challenge for environments running at scale. The code below is a sample script that you can customize to collect this data in 15-minute batches. Code: #!/bin/sh capture() { fileid=$1 pktcap-uw --uplink vmnic4 -o /vmfs/volumes/local-ds-86/vmnic4-inbound-file$fileid.pcap >/dev/null & pktcap-uw --uplink vmnic4 --dir 1 -o /vmfs/volumes/local-ds-86/vmnic4-outbound-file$fileid.pcap >/dev/null & pktcap-uw --uplink vmnic5 -o /vmfs/volumes/local-ds-86/vmnic5-inbound-file$fileid.pcap >/dev/null & pktcap-uw --uplink vmnic5 --dir 1 -o /vmfs/volumes/local-ds-86/vmnic5-outbound-file$fileid.pcap >/dev/null & } #Change the number of iterations to reduce the total time of capture for i in 0 1 2 3 4 5 ...

April 13, 2020 / Akshay / Network, The Tech Center / 4 Comments

Monitoring vmxnet3 Ring Buffer full condition

What is Ring buffer? Ring buffer is a data structure that uses a single, fixed-size buffer as if it were connected end-to-end. This structure lends itself easily to buffering data streams. The useful property of a circular buffer is that it does not need to have its elements shuffled around when one is consumed. (If a non-circular buffer were used then it would be necessary to shift all elements when one is consumed.) In other words, the circular buffer is well-suited as a FIFO buffer while a standard, non-circular buffer is well suited as a LIFO buffer. Circular buffering makes a good implementation strategy for a queue that has fixed maximum size. Source: https://en.wikipedia.org/wiki/Circular_buffer How many Ring buffers does vmxnet3 use? vmxnet3 uses 4 Ring buffers. We can use ethtool -g to check the maximum and current settings for Linux. The command needs to be executed with in the Guest ...

April 2, 2020 / Akshay / The Tech Center, vSphere

Start folding@home face the COVID-19 pandemic together!

What is folding@home? Folding@home (FAH or F@h) is a distributed computing project for simulating protein dynamics. It brings together citizen scientists who volunteer to run simulations of protein dynamics on their personal computers. Insights from this data are helping scientists to better understand biology, and providing new opportunities for developing therapeutics. Folding@home is based at the Washington University in St. Louis School of Medicine, under the directorship of Dr. Greg Bowman. Drs. John Chodera (MSKCC) and Vince Voelz Source: https://foldingathome.org/about/ REQUIREMENTS: Folding@home can run on Windows, Linux or Mac. It can also run on ESXi servers as a virtual appliance. This appliance is recently released by VMware as a fling. Links to requirements for various platforms:

Tips for Gaming Rig owners: The software loves a system with high end GPU and Multiple GPUs. You can put your Rig to use and help.