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vscsiStats Support in ESXi

Posted on the June 26th, 2010 under VMware by Josh Perkins

I tend to recommend using ESXi versus ESX for several reasons.  However, this week I was reminded of the shortfalls ESXi has yet to mitigate.  First, in response to a complaint regarding slow storage performance I responded by gathering metrics using various tools available in vSphere (i.e. performance graphs, esxtop, etc.).  I was quickly reminded vscsiStats functionality, a indispensable storage troubleshooting tool, is not available in ESXi.  Scott Drummonds over at Pivot Point (blog) has provided vscsiStats binaries out-of-band that can be installed within an ESXi server.  The problem is that applying these binaries to ESXi is not supported by VMware nor will VMware release security related patches for these unsupported binaries.  There is no “supported” workaround for running vscsiStats in ESXi.

The second issue was in regards to troubleshooting a vMotion related problem with a virtual machine (well, what appeared at the time to be a vMotion issue).  Basically, the virtual machine would not vMotion regardless of what was tried.  Even after confirming no virtual devices were causing the problem the only solution was to power off the virtual machine and then perform the migration.  I attempted to review the virtual machine vmware.log file after the virtual machine was powered back on.  Unfortunately, the only way to read a vmware.log file is to view it directly from the console of the ESXi host that is running the virtual machine.  Because SSH is not supported in ESXi (yes, it can be enabled) I was not able to read the vmware.log file remotely.  There is no “supported” workaround to remotely view the vmware.log file when using ESXi.

These two issues alone can be deal-breakers for some.

UPDATE 1: VMware made huge steps towards closing the supportability and functionality gap with the ESXi 4.1 release. The two issues identified above have been mitigated as ESXi 4.1 allows supported command-line access locally and remotely via SSH. Additionally, I am happy to report the vscsiStats tool is now available and officially supported in ESXi 4.1 at /usr/lib/vmware/bin/vscsiStats. Great job VMware!!!