How To Configure WOL ESXi5

Distributed Power Management is an excellent feature within ESXi5, it’s been around for a while and essentially migrates workloads to fewer hosts to enable the physical servers to be placed into standby mode when they aren’t being utilised.

Finance dudes like it as it saves ‘wonga’ and Marketing dudettes like it as it give ‘green credentials’.  Everyone’s a winner!

vCenter utilises IPMI, iLO and WOL to ‘take’ the physical server out of standby mode.  vCentre tries to use IPMI first, then iLO and lastly WOL.

I was configuring Distributed Power Management and thought I would see if a ‘how to’ existed and perhaps my  ‘Google magic’ was not working, as I couldn’t find a guide on configuring WOL with ESXi5.  So here it is, let’s crack on and get it configured.

Step 1

First things first, we need to check our BIOS supports WOL and enable it.  I use a couple of HP N40L Microservers and the good news is these bad boys do.

WOL Boot

Step 2

vCenter uses the vMotion network to send the ‘magic’ WOL packet.  So obviously you need to check that vMotion is working.  For the purposes of this how to, I’m going to assume you have this nailed.

Step 3

Check you switch config. Eh don’t you mean my vSwitch config Craig? Nope I mean your physical switch config.  The ports that your vMotion network plugs into need to be set to ‘Auto’ as for WOL to work the ‘magic’ with certain manufacturers this has to go over a 100Mbps network connection.


Step 4

Now we have checked our physical environment, let’s check our virtual environment.  Go to your ‘physical adapters’ to determine if WOL is supported.

This can be found in the vSphere Web Client (which I’m trying to use more) under Standard Networks > Hosts > ESXi02 > Manage > Networking > Physical Adapters


We can see that every adapter supports WOL except for vmnic1.

Step 5

So we need to check our vMotion network to ensure that vmnic1 isn’t being used.

Hop up to ‘virtual switches’ and check your config.  Good news is I’m using vmnic0 and vmnic2 so we are golden.


Step 6

Let’s enable Distributed Power Management. Head over to vCenter > Cluster > Manage > vSphere DRS > Edit and place a tick in Turn ON vSphere DRS and select Power Management.  But ensure that you set the Automation Level to Manual. We don’t want servers to be powered off which can’t come back on again!


Step 7

Time to test Distributed Power Management! Select your ESXi Host, choose Actions from the middle menu bar and select All vCenter Actions > Enter Standby Mode


Ah, we have a dialogue box appear saying ‘the requested operation may cause the cluster Cluster01 to violate its configured failover level for high availability.  Do you want to continue?’

The man from delmonte he says ‘yes’ we want to continue!  The reason for the message is my HA Admission Control is set to 50%, so invoking a Host shut down is violating this setting.


vCenter is rather cautious and quite rightly so.  Now it’s asking if we want to ‘move powered off and suspended virtual machines to other hosts in the cluster’.  I’m not going to place a tick in the box and will select Yes.


We have a Warning ‘one or more virtual machines may beed to be migrated to another host in the cluster, or powered off, before the requested operation can proceed’.  This makes perfect sense as we are invoking DPM, we need to migrate any VM’s onto another host.


A quick vMotion later, and we can now see that ESXi02 is entering Standby Mode


You might as well go make a cup of tea as it takes the vSphere Client an absolute age to figure out the host is in Standby Mode.


Step 8

Let’s power the host back up again.  Right Click your Host and Select Power On

WOL 10

Interestingly, we see the power on task running in the vSphere Web Client, however if you jump into the vSphere Client and check the recent tasks pane, you see that it mentions ‘waiting for host to power off before trying to power it on’

WOL 11

This had me puzzled for a minute and then I heard my HP N40L Microserver boot and all was good with the world.  So ignore this piece of information from vCenter.

Step 9

Boom our ESXi Host is back from Standby Mode

WOL 12

Rinse and repeat for your other ESXi Hosts and then set Distributed Power Management to Automated and you are good to go.

How To Change Default IOP Limit

After my last blog post, I realised I hadn’t actually walked you threw how to change the default IOP limit used by Round Robin.

To crack on and do this we need a SSH client such as Putty

Each change, only has to be made per Datastore which makes things a little easier.

SSH to your ESXi Host and enter your credentials.  We are going to run the command to give us the Network Address Authority names of our LUN’s.

esxcli storage nmp device list | grep naa


A quick look in the vSphere Web Client shows us which Datastores the NAA belong too.


In my case, I want to change the settings for all of the Datastores.  So we will start by checking the current multi path policy to ensure it’s set to Round Robin and the default IOP maximum limit.  Let’s run the following command:

esxcli storage nmp psp roundrobin deviceconfig get -d naa.6000eb3b4bb5b2440000000000000021

A bit like ‘Blue Peter’ here is one I did earlier! Not very helpful.


Let’s run the same command again but for a different NAA.


Excellent, to change the default maximum IOP limit to 1 enter this command

esxcli storage nmp psp roundrobin deviceconfig set -d naa.6000eb39c167fb82000000000000000c –iops 1 –type iops

To check, everything is ‘tickety boo’ enter

esxcli storage nmp device list | grep policy

You should see that each Datastore default maximum IOP limit is set at 1


Performance Increase? Changing Default IOP Maximum

I was reading Larry Smith JR’s blog post on Nexentastor over at El Retardo Land and I didn’t know that you could change the default maximum amount of IOPS used by Round Robin.

By default vSphere allows 1000 IOPS down each path before switching over to the next path.

Now, I wanted to test the default against 1 IOP down each path, to see if I could eek some more performance out of the lab.

So before we do this, what’s our lab hardware?

ESXi Hosts

2 x HP N40L Microserver with 16GB RAM, Dual Core 1.5GHz CPU, 4 NICs


1 x HP ML115 G5 with 8GB RAM, Quad Core 2.2GHz CPU, 5 NICs

1 x 120GB OCZ Technology Vertex Plus, 2.5″ SSD, SATA II – 3Gb/s, Read 250M using onboard SATA Controller


1 x HP 1910 24G

And for good measure the software?

ESXi Hosts

2 x ESXi 5.1.0 Build 799733 using 2 x pNIC on Software iSCSI Initiator with iSCSI MPIO

1 x Windows Server 2008 R2 2GB RAM , 1 vCPU, 1 vNIC


1 x HP StoreVirtual VSA running SANiQ 9.5 with 4GB RAM, 2vCPU, 4 vNIC


1 x HP v1910 24G

Let’s dive straight into the testing shall we.

Test Setup

As I’m using a HP StoreVirtual VSA, we aren’t able to perform any NIC bonding, which in turn means we cannot setup any LACP on the HP v1910 24G switch.

So, you may ask the question why test this as surely to use all the bandwidth you need them to be in LACP mode.  Yep, I agree with you, however, I wanted to see if changing the IOP limit per path to 1, would actually make any difference in terms of performance.

I have created an SSD Volume on the HP StoreVirtual VSA which is ‘thin provisioned’.

Volume Details

From this I created a VMFS5 datastore in vSphere 5.1 called SSDVOL01.


And set the MPIO policy to Round Robin.


VMF-APP01 is acting as our test server and this has a 40GB ‘thinly provisioned’ HDD.


We are going to use IOMeter to test our performance using the parameters set out under

Test 1

IOP Limit – 1000

SANiQ v9.5

Test 1

Test 2

IOP Limit – 1

SANiQ v9.5

Test 2

Test 1 v 2 Comparison

Test 1 Comparison

We can see that we get extra performance at the cost of higher latency.  Now let’s upgrade to SANiQ v10.0 AKA LeftHand OS 10.0 and perform the same tests again and see what results we get as HP claim it to be more efficient,

Test 3

IOP Limit – 1000

LeftHand OS10.0 (SANiQ v10.0)

Test 3

Test 1 v 3 Comparison

Test 1v3  Comparison

HP really have made the LeftHand OS 10.0 more efficient some very impressive results!

Test 4

IOP Limit – 1

LeftHand OS10.0 (SANiQ v10.0)

Test 4

Test 2 v 4 Comparison

Test 2v4 Comparison

Overall, higher latency for slightly better performance.

Test 1 v 4 Comparison

Test 1v4 Comparison

From our original configuration of a 1000 IOPS Limit per path and SANiQ 9.5.  It is clear that an upgrade to LeftHand OS10.0 is a must!


I think the results speak for themselves, I’m going to stick with the 1 IOP limit on LeftHand OS10.0 as even though the latency is higher, I’m getting a better return on my overall random IOPS.

vSphere Web Client: No vCenter

Following on from previous blog post vSphere Web Client: Provided Credentials Are Invalid we have logged into the vSphere Web Client but we don’t actually have anything we can manage.  I think the words we are looking for are ‘man down’.

It all boils down to permissions, we need to logout from the vSphere Web Client and fire up our old trust friend the vSphere Client.

Login with the user credentials you would need to access vCenter Server Appliance, the defaults are U: root P: vmware

vCenter 1

Ah ha, now we see our vCenter (I’m sure you weren’t concerned that all your config had gone)

vCenter 2

Right Click the root level and Add Permission

vCenter 4

Select Assigned Roles and change this to Administrator and then Click Add

vCenter 5

Select your Domain, and change the View to Show Groups First and select Domain Admins and then Add.  Naturally you might not want Domain Admins to have access in the ‘real world’ so select the appropriate Security Group.

vCenter 6

You should see that your Domain\Domain Admins appears under ‘Groups’ Hit OK

vCenter 7

Then Hit OK again to confirm

vCenter 8

TOP TIP: Make sure Propagate to Child Objects is ticked

Exit the vSphere Client and login to the vSphere Web Client using https://<IP Address>:9443/vsphere-client/

vCenter 9

Boom, we have a vCenter Server, Hosts and everything!

vSphere Web Client: Provided Credentials Are Invalid

So you have battled your way through installing vSphere 5.1 and you are finally at the point when you are ready to login, but you get the epic fail ‘provided credentials are not valid’.  By now you have probably tried every format under the sun to login.





But nothing is working, what’s going on? The vCenter Server Appliance is showing that Active Directory Authentication is ‘Enabled’


Well to be honest, the vCenter Server Appliance is telling ‘porky pies’ it hasn’t actually done squat with Active Directory and this is the reason you can’t login.  So let’s get that sorted.

Login to the vSphere Web Client using https://<IP Address>:9443/vsphere-client/

Enter the username and password you use to login to the vCenter Server Appliance, the defaults are U: root P: vmware


Hooray, you are in the vSphere 5.1 Web Client! We need to select Administration from the left hand menu


Select Sign-On and Discovery and then Configuration followed by clicking the + in the top left under Identity Sources


Voila, this is where we need to do the Active Directory Authentication as follows:

Identity Source Type select Active Directory

Name: vmFocus

Primary Server URL: this is your Primary Domain Controller, the format is ldap://vmf-dc01.vmfocus.local

Base DN For Users: this is CN=Users,DC=vmfocus,DC=local

Domain Name: this is vmfocus.local

Domain Alias: this is vmfocus

Base DN For Groups: this is CN=vCenter_Access,rootOU=SecurityGroups,DC=vmfocus,DC=local

Authentication Type: Password

Username: vmfocus\vmware.service

Password: password

Once you have entered all this in, hit Test Connection

SSO 11

TOP TIP: If you don’t know your base DSN, fire up ADSI EDIT and it’s easy to see

If all is successful, you should see ‘the connection has been established successfully’.


We now need to tell vSphere 5.1 to use the Active Directory to allow users to login.  Select your domain and click Add to Default Domains


You will get the warning ‘having multiple domains in the Default Domain list might result in locked user accounts during authentication’ I think we are willing to take the risk, considering we can’t even login yet.  So hit OK.


Fingers crossed, you should see your domain listed at the bottom under ‘Default Domains’ Don’t forget to hit the save icon.

SSO 10

Right then let’s give it a whirl, logout and try login with an Active Directory User who is in the Group vCenter_Access

SSO 12

Boom it works! But hold on a minute, I don’t see my vCenter or Hosts.  Hold tight, we will cover this in our next blog post.