I had 8 paths go down to a dead state on an ESXi host.  The paths were MRU via Fiber Channel to a storage array.  One path worked and it was configured as RR path.
I knew this wasn't a physical issue, it had to be a software/configuration issue on my host because there were:

No storage array errors
Additional hosts in the cluster had no problems
One path still worked from the HBA

Looking at the log (/var/log/vmkernel.log) I searched for one of the LUN identifiers, in my case ":L30" which Continue Reading...

During datastore creation in vSphere using the Nimble vCenter plugin, I get the following error:
A general system error occurred: esxi1: CHAP setting not compatible. hba=vmhba33
In vSphere Client I went to my ESXi host then Configuration, Storage Adapters, iSCSI Software Adapter.  Taking a look at vmhba33 Properties then CHAP... I see that there was a CHAP setting in there for an old Drobo system I had connected at one point.

Changing the option to Do not use CHAP resolved my issue.  I'm not Continue Reading...

Here's an ESXi console script to loop through each Nimble eui.* adapter and set IOPS=0 and BYTES=0 (per Nimble recommendations).
for x in `esxcli storage nmp device list | awk '/Nimble iSCSI Disk/{print $7}' | sed -e 's/(//' -e 's/)//'`; do
echo $x
esxcli storage nmp psp roundrobin deviceconfig set -d $x -t bytes -B 0;
esxcli storage nmp psp roundrobin deviceconfig set -d $x -t iops -I 0 ;
esxcli storage nmp psp roundrobin deviceconfig get -d $x;
done
Note: If you change the order above and set Continue Reading...

I've spent some time exploring and studying the use and configuration of VMware Flash Read Cache (vFRC) and its benefits.  These are my notes.
Useful Resources

VMware Flash Read Cache 1.0 FAQ
vSphere 5.5 Flash Read Cache Documentation

On a guest virtual machine, vFRC is configured in Disk configuration area.  The virtual machine needs to be on version 10 hardware.  vSphere needs to be minimum version 5.5.

Benchmarks
I took a baseline benchmark of a simple Windows Server 2016 virtual machine Continue Reading...

This will be an evolving post as I document/note the installation process and some configuration and testing.
I'm installing VMware vSphere 6.5 under my current virtualization platform to give it a spin. I'm most curious about the web interface, now that it has moved exclusively in that direction. I *HOPE* it is much better than my current vSphere 5.5 U1 deployment.
9:39PM Installation
So far, installation is going well.  As a simple test setup, I created a virtual machine on my current vSphere Continue Reading...

CPU Ready value is cumulative between the number of vCPUs the VM is assigned. For example, a one vCPU VM has the measurement of 1000ms. For a VM with two vCPUs, the same performance drop would rise to 2000ms, or 1000ms per vCPU. For a VM with four vCPUs, it would be 4000ms.
Realtime Monitoring
CPU Ready / (interval * 1000) * 100 = Performance Penalty
Statistics Rollup Intervals
vCenter defines the following default intervals for rollups:

Real-Time: 20s interval (20 seconds)

CPU Ready / (20 Continue Reading...

Run the esxcli storage vmfs extent list command to generate a list of extents for each volume and mapping from device name to UUID.
You see output similar to:
Volume Name VMFS UUID Extent Number Device Name Partition
------------ ----------------------------------- ------------- ------------------------------------ ---------
esxi-local 4e0d86e1-0db6f826-6991-d8d3855ff8d6 0 mpx.vmhba2:C0:T0:L0 3
datastore1 4d4ac840-c1386fa0-9f6d-0050569300a7 0naa.6006016094602800364ce22e3825e011 1
vmfs5 4dad8f16-911648ca-d660-d8d38563e658 Continue Reading...