VMware local disks needs WriteBack Cache

When using VMware servers and local hard drives, make sure one uses a battery backed cache card.

What an operating system does when it wants to write to a drive, is it waits for confirmation from the drive/controller to make sure the data is written before it sends more data (write-through).  This is VERY SLOW.  Windows gets by this by doing some creative caching that eats up system RAM; where as VMware, relies solely on the hardware.  The alternative is write-back, where the drive write confirmations are done by the controller, the data is cached while waiting for the disk to actually write it, and the OS continue to sends more data.  In a way it is kinda sorta like TCP vs. UDP.

Just to test this...I have an HP Proliant ML310 with four 250gb 7200rpm SATA drives in a RAID 10 configuration; the RAID controller is a SmartArray P212.  Vmware v5.5 is installed.  The test VM is a Win7 x86 machine w/ a single CPU and 4gb of ram.

This image, the VM on is on the RAID...baseline, as you can see the performance is dismal.

This image, I turned on the cache that is on the hard drives (the hard drive cache, not the RAID card cache).

This image is the VM on a single SATA 160gb drive connected to the systems board's SATA controller.  Notice how a single drive is significantly faster.

This image is with a 512mb battery backed cache installed on the RAID card.

Desktop VM Optimization

Running Windows7,8, or 10 as a VM whether it be VDI or just a VM the OS is bloated and wasteful.  VMware has a fling that helps this, (VMware flings are items created by VMware but are not fully supported).  TheVMware OS Optimization tool analyses a VM and compares it to a list of best practices for optimizing resources.


VMware 6.0 U1 & NetApp upgrade random thoughts...

One of the downfalls of v6 is that the “Storage Views” tab is gone…..which I used primarily to identify stale VMware snapshots.  The alternative is to use PowerCLI:

OR I found this handy tool:

http://www.robware.net/  Among many other nice things, it does give a nice single pain to view all VM's that have snapshots.

Do you have an email domain with only two letters?  IE bob@AB.com?  If so configuring email alerts is an issue.  Setting the email address with a two letter domain name will error out via the WebClient.  It works fine via the C-Sharp client.

VMware VCenter v5.1 Update 1 will not work with Windows 2012r2; it must be update 3, VMware-VIMSetup-all-5.1.0-2308386.

The web client is light years better than v5.5 or 5.1.  IMHO it still needs work.  Logging on to it takes too long, it still drags, I find myself opening a couple of windows to the same vCenter to get the same info that I would normally get with the thick client.  The Web-Integration piece, is HUGE, the download is something like 100mb, I thought this was supposed to be a lightweight-client?

One of my machines had a problem with the Web-Integration services, it would install, but not register.  Even after installing it, the prompt to install it would show up on the logon page.  The solution was to download a slightly newer version of the client from vmware.com.

If one ever has SRM or any other tabs not showing up, restart the Vmware vCenter Web Service.
I have experienced where many options not showing up using a domain administrator account, but yet the options where all there using administrator@vsphere.local.   Chances are permissions got messed up.  Fortunately I had two sites to do a stare and compare between.

The NetApp Virtual Storage Console, is HORRIBLE!!

-There is no real c-sharp plug in, when one clicks on the plug in the C-sharpe client, it gives a message saying that the webclient must be used.
-SnapMirror jobs cannot be modified if a two character email domain is used.  The work around it to edit an XML file.
-The plug in often fails, and requires a bunch of tinkering to re-register it.  See https://vcenterfqdn/MOB
-SnapMirror backup jobs, there is only three statuses used, failed, successful, or completed with errors.  If one wants to dig deeper consult the email logs.

.....work in progress......