Author Archives: Wu

About Wu

VCP, MCSE, CCNA

Login To The Query Service Failed When Search Virtual Machine

You may see following problem if you login vCenter  Server 6.0 by vSphere Client:

Login to the query service failed.

The server could not interpret the communication from the client. (The remote server returned an error: (500) Internal Server Error.)

That’s because “Use Windows session credentials” checkbox is selected. Deselect it and give it a try.

Refer KB Searching the Inventory with the vSphere Client fails (2143566)

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Virtual Machine Cannot Get DHCP IP Address

Just a quick post. When virtual machine cannot get DHCP IP address the first thing you want to check is firewall. Whatever Windows firewall or physical firewall. You should make sure UDP port 67 and 68 are not blocked. Otherwise you  will see the virtual machine gets 169.x.x.x IP address only.

The two  ports is required for DHCP client to query IP addresses. The methodology is introduced in RFC document.

DHCP uses UDP as its transport protocol. DHCP messages from a client
to a server are sent to the ‘DHCP server’ port (67), and DHCP
messages from a server to a client are sent to the ‘DHCP client’ port
(68). A server with multiple network address (e.g., a multi-homed
host) MAY use any of its network addresses in outgoing DHCP messages.

I also got some ideas in this post.

Adobe Flash Player Out of Date on vSphere Web Client

You may see ‘Adobe Flash Player Out of Date’ on Chrome when you open vSphere Web Client. Click the text Chrome will update Flash Player automatically. But in some cases it doesn’t work due to maybe your Chrome is controlled by company policy or internet problem to Adobe.com. I found an article to show how to offline fix the issue. You can download Flash Player for Opera and Chromium-based browsers – PPAPI in official Adobe KB article.

You may also want to check out my other articles about Flash issue on browsers.

Flash menu appears when right click on vSphere Web Client in Chrome

Cannot open vSphere Web Client on IE11 on Windows 8.1

Network Latency on Virtual Machine

Slight network latency may cause application problem  on sensitive virtual machines. Even the network responding time is just 3 or 7 ms. There is a way to improve the  stability of responding latency – Enable RSS on NIC.

Network traffic is handled by single CPU core when RSS is disabled. Enable it will distribute the workload to 4 cores by default. You can increase CPU for RSS by change registry.

To summarize the solution. Go to Device Manager -> NIC properties -> Advance -> Find RSS option  and enable it. You will see 2 – 3 network drops when applying it.

You can refer following articles for detail.

Poor network performance or high network latency on Windows virtual machines

Virtual Receive-side Scaling in Windows Server 2012 R2

Regarding increase CPU for RSS. Read following article to learn how to modify it.

Setting the Number of RSS Processors

vRealize Operation Manager Installation Pending on install.sh

If your company implemented firewall and blocked public NTP server, you may see installation of vRealize Operation Manager pending on ./install.sh on console. That’s because the installer tries to negotiate with NTP server http://www.iana.org. The firewall blocked the traffic.

VMware TAM Manager Shan told me  there are two options on firewall to block traffic: REJECT and DROP. REJECT means firewall responding to the request and let source device knows it’s rejected. DROP means firewall immediately ignores the request and no responding to source device. Looks like there is a bug in vROPs code that it hung if NTP request gets drop and no responding.

The workaround is create a port group without physical uplinks and install vRealize Operation  Manager. Then move it to proper network after installation  is completed. You can configure correct IP addresses when import the OVF file so later on you just need simply move the network.