Blog   »   Finalizing installation tasks (VMWare on a Dell server)

By administrator Site Admin at 4:45 pm

Once your VMWare Host OS has been setup, don't forget to setup your systems optional features. This list will be very useful to those administrators who are primarily offering remote support to their colleagues / office systems, and doing this right may mean the difference between “just an outage” and “support nightmare”. So… for that reason, we’ve decided to document our experience and best practices we are adhering to when setting up a remote site for SMB.

These features should not really be "optional", as it is simply best practice to set up all of these, or as many of these features you will later find very useful.

vSphere options:

Automatic startup
This feature allows your system to automatically boot up your guest OS once the ESX host is up and running. This comes very handy when your ESX host sits in an environment where there are no administrators available 24/7 to start the guest OS in an event of failures, such as power outage, high temperature and other unforeseen issues you or your client may encounter.
If your DHCP and DNS servers are running on a virtual system – don’t forget that you will need these systems started before your office systems can obtain an IP address – allowing them to perform basic functions such as get out to the internet, allow you to remotely connect to your site etc etc.
To setup the auto-start of your guest OS(s), in vSphere, go to Host > Configuration > Software > VM Startup and Shutdown > Properties

Check the options for

-    Allow virtual machines to start with the system
-    Continue immediately if the VMware tools start…
-    120 seconds seems like a reasonable value to leave here.

Make sure you highlight the systems in the startup order window below. Good practice is to start systems in the following order:

1.    Your DNS / AD system
2.    DHCP server (if not on the same box)
3.    E-mail server
4.    Other (or all other) VMs

Word of caution here… make sure you research this thoroughly… there are certain software versions of ESX software (we can’t say more) that have a known bug – automatic start doesn’t work even though you’ve done everything you were supposed to. What we can say is – vSphere 5.1 and 4.1 work well :)
NTP server – set this up using your vSphere client (Host > Configuration > Software > Time Configuration > Properties). Make sure you enable the client after configuring the NTP server. We are using, but there are many servers you can use. Setting this feature up and starting the service does not require system reboot.

USB Pass-through:
This is what we refer to “sweet” setup. While we all understand we should have the third party software installed for backups, offsite tape drives and all that good stuff… reality is that huge percentage of servers are being backed up to a USB hard drive. Yes, it’s not the best way to go about backups, but it is what we all do at some point.
VMWare explains this feature on the following page:
What we’d like to add is that setting this feature up requires a restart of your ESX host. On the guest OS, you would simply go to Edit Settings > Add device > Add USB Controller. After you apply this change, you can connect the USB hard drive to your ESX host, and then add it to guest OS following the same procedure from above: Edit Settings > Add device > Add USB Device.

One word of caution here: Please do a thorough research about external USB HD you are purchasing, as many are actually not supported for backups by newer MS Operating Systems due to restrictions in default block size (or some other nonsense that will get in the way). So be careful here.
There are many other concerns here, especially if you expect vMotion to work… don’t connect the USB hard drive this way – that’s all we can tell you and spare you from having to read several pages explaining limitations of directly attached devices. If you have a single ESX system and many systems on it – nothing to worry about, this is the way to go.

System options (we are dealing with Dell Power Edge system in our case, so we are using Dell Open Manage)
In order to install Dell Open Manage on an ESX host, you will have to contact Dell (or other manufacturer, depending on your MFR and system version you are using). You will have to obtain the proper version for your environment and have it installed on:

1.    Your ESX platform (this will require a reboot of your ESX host):

a)    Download the proper software from your vendor
b)    Install software on your ESX(i) in maintenance mode: esxcli.exe --server software vib install –d   (*)
c)    After installation, don’t forget to restart your ESX host for changes to take effect

2.    Your Guest OS (contact vendor for supported versions) – this is an executable file, no need to explain this further :). OM can be installed on a guest OS, or any system in your office. You may or may not have to

(*) if you are having problems accessing your host using SSH, we have seen a problem with VMW firewall not allowing port 22 by default. This is something you should check carefully as any changes you can make here (vSphere; Configuration > Software > Security Setup) may cost you your ESX environment and that’s… no fun.
This may seem like a complicated setup, but server vendors are usually very supportive and knowledgeable and they will more than likely make this installation a breeze. It is well worth it…

One of the most important options to setup is the Thermal Shutdown
(Start Open Manage from any browser, make sure you check the box “ignore cert errors”. Once you log in > System > Shutdown > Thermal Shutdown). This feature will automatically shut down your host in an event of high temperature, so you can avoid serious damages to your system due to overheating. Safe value to set the automatic shutdown at is 45 degrees Celsius. Low thresholds don’t matter as much, but let’s say you set them up to -1.0C, and you should be fine.

Our version of Open Manage (7.2.0) supports “Shutdown OS first” option, which we highly recommend.

Operation of your PERC controller (done in OM, via any browser):
This is something we would like to point out to those of you who have had the opportunity to miss this option during system setup, or to make the mistake when setting the system up… no worries, we’ve seen it all and we’re not ashamed to admit it. Instead of keeping this as a secret, we’d like to share it with you.
The easiest way to notice there’s a problem with system configuration is if you are getting I/O errors related to latency on a system that DOES NOT use iSCSI. This problem is often related to misconfigured PERC controller – you are not using your PERC cache!

Dell recommends their PERC controllers to use the following policies: Adaptive Read Ahead, and Write Back. If you don’t have these policies defined, you may experience latency errors, documented in vSphere. What this means is – your controller is being used as one without cache memory, and your system’s performance will be greatly reduced.

Our recommendation is that you change this setting by doing the following:
In OM (or OMSA, as Dell refers to it), go to System > Storage > Controller (it will be listed by name) > Virtual Disks
Now click on the drop-down menu, and choose “Change Policy”, then EXECUTE. Set your read policy to “Adaptive read ahead” and your write policy to “Write back”. Your Disk Cache policy should be enabled. Click on APPLY.

As always, before doing this, it is highly recommended that you backup your entire system, as you will need to be able to restore it from backups in an unlikely event where something goes wrong. We’ve had no issues while doing this “on the fly” on an ESX system hosting multiple guest operating systems. Reboot was not required, but it is recommended that you “leave your system alone” for at least couple of hours or more after this change. We would not recommending performing updates, backups or any other disk-intensive operations right after the change was made. Leave it for tomorrow…

Needless to say, it is critical that you choose your controller wisely when purchasing your system, and we can highly recommend H7xx class of array controllers, with cache. Smaller and more affordable units are available, but you will outgrow them fast in SMB environment, and changing them down the road will more than likely end up being a very expensive and risky operation.

Just like with almost anything in the IT world these days, if you’re not comfortable doing this yourself, you can always reach out to experienced vendor for assistance when it comes to system setup and documentation, but also if you need assistance with best practices, documentation or final “crossing the t’s and dotting the i’s”.