Tag Archive: xencenter



A brand new XenServer pool in an external office had an interesting problem. Two hosts were added to the pool and yet they could not access two mounts on a NetApp filer.

A repair of the SR would give an error message:

There was an error while attempting to mount the NFS share.

Three other XenServer hosts had no issues.

Checked all the obvious and yet they would not repair. I considered a reload but how would that solve it?

Tried using the mount command to mount one of the shares to a directory and received an error that the server rejected the request.

I mentioned this to the administrator who owned the filer and it turns out he likes to use host lists to control access.

He added the hosts to the list and I was able to repair the SRs.

 

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Some errors were encountered…..


My xencenter events start displaying blank errors which when expanded showed:

Some errors were encountered. See the XenCenter log for more information.

I searched for the log file as it was not in an obvious place.

It’s easy to forget xencenter is a client application. After hunting around I found it was stored at:

C:\Users\<USER>\AppData\Roaming\Citrix\XenCenter\logs\XenCenter.log

Note: If you don’t see “AppData” enable show hidden files and it will appear.

Noticing the time of the error; I searched the log file and found the following error messages:

2016-09-29 13:24:11,019 ERROR XenAdmin.Actions.AsyncAction [252] –    at System.Net.HttpWebRequest.GetResponse()

at XenAdmin.Actions.GetHealthCheckAnalysisResultAction.GetAnalysisResult(String diagnosticToken, String uploadUuid)

at XenAdmin.Actions.GetHealthCheckAnalysisResultAction.Run()

at XenAdmin.Actions.AsyncAction.RunWorkerThread(Object o)

at XenAdmin.Actions.AsyncAction.RunWorkerThread(Object o)

It can be a confusing message but I remembered the new health check analysis ability with Xenserver 7.0. It turns out a couple of pools were trying to use the logged in account rather then the actual Citrix site account.

I changed the configuration to the correct account and these errors went away.

 


There was an odd issue with one of my xenserver pools.  I looked at xencenter and found the following as offline pool SRs:

DVD drives
Local storage
Removable storage

Rather strange and I was too busy to review the log files for errors. I wasn’t sure when those appeared and of course nobody knew anything.

How to get rid of them?

Trying the GUI had no options to remove them.  Time for the command line.

Right-Clicking an entry and selecting properties, I copied the UUID.

I opened a shell and entered:

xe sr-forget uuid=<pasting the UUID>

Repeated two more times and the entries disappeared.

Back to regular work……


One of the odd things about xenserver (there are a few) is the way you configure a search domain for /etc/resolv.conf. You can’t simply edit the file and it’s not part of the install.

You have to use the xe commands to establish a permanent search domain.

From the console on the host:

  • You need UUID of the management NIC; the following command will list it:

xe pif-list host-name-label=<hostname> management=true

  • Add the search domain by entering:

xe pif-param-set uuid=<uuid from above> other-config:domain=<your domain>

Note: you can tab through the UUID by simply entering a couple letters and pressing the tab key.

To enter multiple search domains, simply separate by commas:

xe pif-param-set uuid=<uuid> other-config:domain=<domain>,<domain>

  •  Reboot the host and the search domain line appears in /etc/resolv.conf

 

Acknowledgement time!


One thing I have noticed on the Net; information about Citrix can be lacking at times.

I had an instance where a resource pool was established and the thinking behind it was wrong. I wanted to destroy it. I started Xencenter and accessed the doomed pool. I removed all the extra Xenserver hosts by simply right-clicking the entry and selecting “Remove Server from pool”

When it came time to kill the master, there wasn’t an option. I tried the xe options of eject and forgetting but they gave errors.

As mentioned, the Net was lacking on information. So I basically started hunting around thinking “it can’t be a reload!” I didn’t want to go through patching again.

I looked at the Xencenter window tab for Pool and sure enough there was an interesting entry!

Make into standalone server

I selected the master host, clicked “Pool” and selected the option. It ran really fast and the pool entry disappeared with the server showing up at the bottom of list of resources. I expected it to reboot but it didn’t. I gave it a reboot for good measure and then added the ex-master as a host to the correct pool.

 


With our new XenApp effort; we are going to attempt VDI for our Linux users. Previously, we were using Sun Terminal servers but Citrix stopped supporting it awhile ago and now we have to change.

Our XenServer is version 6.5. Before you attempt to install xentools on any of your guests; make sure you have installed Service Pack 1 and all the suggested patching. Otherwise, you might find yourself having to update xentools again.

Installing Xentools is easier then I remember from a failed XenServer project a couple years ago. Well, the XenServer effort failed due to many mistakes by Citrix  and I probably flushed my brain of this experience as fast as possible.

To install Xentools on RedHat.

  1. Start XenCenter.
  2. Login into your Redhat guest as root.
  3. From XenCenter; click the link to install xentools or right-click your guest and select install xentools. This will load the ISO on the DVD.
  4. From your Redhat guest; enter:   mount /dev/dvd /mnt
  5. Enter: cd /mnt/Linux
  6. Enter:  ./install.sh
  7. Reboot after it finishes.

Surprisingly simple to do.