Citrix Mobility Warszawa 2013

Written by Pawel Lakomski on Listopad 15th, 2013

19 listopada odbędzie się w Warszawie konferencja Citrix Mobility 2013. Agenda do znalezienia tutaj. Udział w konferencji jest darmowy.


XenApp Web Interface error: The correct version of web interface is not installed on this computer

Written by Pawel Lakomski on Listopad 14th, 2013

This is an error you may get when you open Web Interface Management console (for XenApp 6.5) and try to open XenApp Services Sites or XenApp Web sites node. Additional problems include: Web Interface cannot be uninstalled from Control Panel (error 1603) or repaired from the installation binary.

Citrix KB CTX13820 points to possible IIS corruption and advises to reinstall IIS and Web Interface. However, the solution might be much simpler – check if IIS Admin service is running in Windows. If not – start it and try to open Web Interface Management, it should work ok.


VMware Update Manager Download Service to download them all…

Written by Pawel Lakomski on Listopad 1st, 2013

Many times vCenter Server and Update Manager reside on the same server and for security reasons there is no access to internet from this machine. So what do you do to patch your ESXi hosts? You can download bundles from an other server and import them into Update Manager. You can try patching the hosts manually, without UM. Or you could try VMware Download Manager. This tool is little known but can save you a lot of trouble by downloading patches and creating a store Update Manager can use on a another server with access to the internet.

As vSphere 5.1 documentation says „VMware vSphere Update Manager Download Service (UMDS) is an optional module of Update Manager. UMDS downloads upgrades for virtual appliances, patch metadata, patch binaries, and notifications that would not otherwise be available to the Update Manager server.” So this is exactly what we need. First things first though so let’s have a look on Download Manager’s requirements:

  • it cannot share the same machine with Update Manager (otherwise, why would you need Download Manager in the first place?);
  • previous versions of UMDS must be uninstalled before you try to install it from vSphere 5.1 installation media;
  • server to install UMDS must be x64;
  • and last but not least – access to the internet on the server you intend to install DM to.

Ok, let’s start the installtion from vSphere 5.1 installation media \umds folder. It is pretty straight-forward. Go through the welcome screen, license agreement, etc.  If you don’t have MS SQL server it can install MS SQL 2008 R2 Express edition for you. If you do, you will need to create 32-bit ODBC as UMDS is 32-bit applications. You will be able to configure proxy as well. Now when the installation has finished, let’s have a look on the tool. First mind that it is purely CLI-based tool so there is no GUI. Secondly, there is only one binary to run and that is (by default located in Program Files x86\Vmware\Infrastructure\Update Manager):


Run it and you will see all possible switches. -D will start download:

vmware-umds.exe -D

but wait a minute. First, let’s configure what should be downloaded. To list supported platforms use:

vmware-umds.exe --list-host-platforms

and the outcome will be something similar to:

[2013-10-29 00:40:59:876 '' 2244 ALERT]  [logUtil, 265] Product = VMware Update
Manager, Version = 5.1.0, Build = 1022478
Supported ESX Host platforms:

To enable download for ESX 4.1 insert:

vmware-umds.exe -S -e esx4.0.0

Make sure that the configuration is ok:

vmware-umds.exe -G

To download the updates for host / VA versions you enabled:

vmware-umds.exe -D

And finaly to configure the store that will be used by Update Manager and export downloads to it:

vmware-umds.exe -E --export-store <path_to_the_store>

Simple as that. Now configure Update Manager to use that store and voila!. There is another tool that comes with UMDS and it is VMwareupdateManagerUtility.exe located in the same folder. It will allow you to change proxy and database settings later on if necessary.


ESXi cannot resolve names

Written by Pawel Lakomski on Październik 28th, 2013

I have recently encountered a strange problem when an updated (ESX 4.1 -> ESXi 5.1) host would not connect to the vCenter. The host would be up and respond to ping but no connection to vCenter. A usual troubleshooting step  pinging vCenter server from the host showed that the vCenter server’s name could not be resolved. Ping via IP worked fine. Checking hosts file showed that all entries were fine. Worse, the host was not able to resolve localhost either – hence problems wih starting services. So what has changed?

After the upgrade has been done, I added DNS servers to the host’s configuration. So let’s try to remove them. After I commented out the entries in resolve.conf file – bam! – everything started working again. I restarted the management services and the host connected to vCenter. But, well, I needed these DNS entries.

Finally I found out that the /etc/nsswitch.conf was completely empty. I am not sure if it was like that before. The simplest way to resolve the problem was to copy a correct file from another host, review it to make sure all settings were fine, replace it on a faulty host and reboot the server. After the reboot the server connected correctly to vCenter and all names resolution worked fine.


Transparent Page Sharing nowadays

Written by Pawel Lakomski on Październik 23rd, 2013

I run accross a really great article by Jason Boche that puts some light on what can gradually happen to the consolidation when newer operating systems are intruduced. It’s really eys-opening and this is something that can slip our attention as it happens gradually. It all focuses on the fact that large pages (2MB) are not considered by Transparent Page Sharing mechanism. For two reasons basically: 1) because the possibility of matching pages is much lowe and 2) because it is much more work-intensive. As a result as newer OSes are introduced and begin using large pages, the memory saved by TPS is smaller. It’s yet another case of performance vs. resurce saving. You’re the one to choose.

I really appreciated tests done by Jason to check how much memory can be saved by forcing small pages. Be sure to check out his article.


Citrix XenApp Server: Protocol Driver Error – fixed the easy way

Written by Pawel Lakomski on Październik 17th, 2013

When using Citrix Presentation Server 4.5 one day you may be welcomed with the following message when trying to open a hosted application:

Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. Protocol Driver error.

As described in Citrix KB article CTX136826 this can be fixed by recreating ICA-tcp listener in TS configuration. However, as noticed by my colleague Artur, one can make it work by simply disabling and re-enabling this listener. No need to delete and re-create it! :-) Hope that helps someone.


Konferencja IT InfoMEET – zaproszenie

Written by Pawel Lakomski on Wrzesień 3rd, 2013

Już 14 września zapraszam na bezpłatną konferencję IT InfoMEET, na której będę miał przyjemność zaprezentować temat „Cloud computing: jak organizacje korzystają na chmurze prywatnej”.

Miejsce: hotel Radisson Blu Sobieski, Plac Zawiszy 1, Warszawa. Od 9:00.

Do zobaczenia!


A virtual machine gone bad – how to shut down an unresponsive VM

Written by Pawel Lakomski on Sierpień 30th, 2013

Some time ago I encountered a problem with a VM that didn’t want to shut down. First, the problem was the VM was the vCenter server. And I mapped a CD via vCenter to itself (mind: from a local disk, not from a datastore). After I started copying data from the CD to the VM it became frozen. As VM monitoring was configured and the machine stopped sending heartbeats, VM monitorin decided it was time to shut down and power on the VM. The shutdown was stuck at 95%. Now, I know there are many stories about hanged VM all over the Internet but stay with me.

A usual stuff (service mgmt-vmware restart) did clear the status of the poweroff in progress but the VM was still running as I was going to learn. The VM appeared as inactive and the display name changed to unknown. I removed the machine from inventory and tried to register it again but with the same effect. apparently it was still running on the host. I managed to change the name of vmx file and register it correctly but of course it did not power on – the virtual disk files were locked.

In this case find the virtual machine world id:

vm-support -x

and kill the machine:

vm-support -X VM_world_id

Answer „no” to screenshot question and „yes” to the other two. It’s gonna take some time. After that the machine could be registered correctly and I could power it on.


Windows 8.1 enhancements for business

Written by Pawel Lakomski on Lipiec 29th, 2013

Will new Windows release introduce substantial changes that may convince corporate IT to adpot it earlier? I remember my colleague desperately trying to get an executive’s brand new iPad working with office wifi. The authentication to the network was domain based. This is not so new a problem but I guess it will steadily grow as BYOD becomes more and more popular. Another example: how many of use have a (personal) mobile phone next to you computer? Everyone? And how many of you can use it to access corporate resources (like check this Excel sheet while you’re away from keyboard). Nobody? With Windows 8.1 new feature called Workplace Join IT administrators will be able to precisly which resources can be accessed from a personal device without giving too much permissions. It is quite neatly called „a middle ground between all or nothing access”.

Workspace Join works hand in hand, and is kinda extended by a feature called Work Folders. It is similar to old offline files synchronization but you don’t need a device in a domain or domain access. Files will be synchronized automatically and can be accessed from different devices. Corporate Dropbox by Microsoft?

One trick to overcome worries over BYOD security is an introduction of Remote Data Removal possible if a device is lost or stolen. 3rd party tools already exist but an embedded feature will probably convince IT departments to use it more. I will galdly welcome another improvement – support for Miracast. And, last but not least, option to boot directly to Desktop as well as „Improvements have been made to better support users who prefer a mouse and keyboard experience to access applications.” – namely the start menu is back.

More Windows 8.1 enhancemets can be found here. Windows 8.1 preview can be downloaded here.


MCSE: Server Infrastructure

Written by Pawel Lakomski on Lipiec 26th, 2013

I have finally taken time to pass 70-413 and 70-414 and I obtained MCSE: Server Infrastructure for Windows Server 2012. The exam 70-414 was really tricky so be sure to prepare well before taking it.

Too bad Exam Ref 70-414 book by Microsoft Press has been again posponed, this time for October 2013. Some time ago it was September, even earlier April, etc. Moreover, say good bye to old-style classic Training Kits from Microsoft Press. Now to learn new skills you  can use two types of paper resources: Exam Refs and Training Guide. The difference is, as explained on MS blog: „Exam Refs are designed to give experienced professionals an exam objective-by-exam objective tour of the certification exam.” while „The new Training Guide series is a wonderful orientation to the job role for a less prepared candidate.” Which is good – if you’re more familiar with the subject you can buy a shorter (and cheaper) Exam Ref and do your research with Technet. Which I did for MCSE as Exam Ref is rather a condensed compendium of topic you need to learn to take (and pass) the exam.