Working with any large software suite can be frustrating, at best. VWware's vSphere 4 production is not immune to this frustration. Over the last few months, I have been involved pretty heavily in the installation, setup, and maintenance and a virtual environment. That said, I have learned a few vital things that I thought I would enumerate here so I can find them later. :-)
1) Installing ESX servers and using the vSphere vCenter Server management client. The major release that I have been working with is 4. Sooooo, I would assume that any minor relase would work with any other minor release. But NOOOOOO, leave it to VMware to over-complicate everything. Lesson here:
- if you have more than one ESX server and are using the vCenter Server, here is the scoop: Remote management from the client is easier when all ESX servers are the same build. Additionally, the management of the ESX servers through the vCenter Server will not work if the vCenter server is 4.0 and one or more of your ESX servers are 4.1.x. If you have this setup, you will most likely end up with an error along the lines of "vmodl.fault.HostCommunication"...although I admit I don't recall the exact error string. There are two fixes that I found for this. The first one involves updating the vCenter Server....but this must be on a 64-bit machine as the update is not supported on the 32-bit machine. The second fix is that of downgrading the ESX server to the 4.0 build. The downgrade wasn't bad AND more importantly, the downgrade (or upgrade) allows you to preserve your data store.
2) View Connection Server: If the machine you are trying to serve up shows "no desktop source available," there are a couple of possilbe issues here.
- You may not have the agent installed in the virtual machine
- The name you have used for your machine may not match the name on your client settings if you specified a particular desktop for one user
- Sometimes this error has shown from me when there has been a DNS issue on the domain.
3) Cloning/migrating:
If you have to clone or migrate a virtual box and will be serving it up via the View Connection Server, it proved neccessary for me to run the View Connection Agent installer again and select "Repair." Although I used customization settings to ensure differing hostnames after a clone, I still found that the View Manager Server would NOT see the machine until I "repaired" the installation.
Friday, September 10, 2010
Friday, June 25, 2010
Windows 7 and VMWare
I have had the "distinct" pleasure of building a group of virtual workstations and using different versions of Windows operating systems in their creations. I have some open questions still and have even presented them to VMWare in the hopes they will answer the questions and save me what may turn out to be days of research/trial-and-error. However, I have had some interesting issues and thought I might post them here.
The biggest issue that I had with creating the virtual Windows 7 boxes (AND Windows Server 2008 R2) was that I was getting this error message:
"A required CD/DVD drive device driver is missing. If you have a driver floppy disk, DC, DVD, or USB flash drive, please insert it now."
Before explaining the fix that I "found" for this error, I should probably include the other hardware and software I am working with for this little project:
- 1 ESX Server installed on a Penguin server
- 1 Penguin Desktop - Vista
- 2 Windows 2003 R2 Servers (one for the VMWare vSphere/vCenter Server, one for the VMWare Connection Server
- 1 IGEL Thin Client with both RDP (5 and 6.1) support and VMWare View Client installed.
- ALL VMWare software is at least release 4.0.0.
- Guests (Virtual) OS's
- XP 32-Bit
- XP 64-Bit
- Vista 32-Bit
- Vista 64-Bit
- Windows 7 32-Bit
- Windows 7 64-Bit
- Red Hat Enterprise Linux 5.1 (HAD to have at least one Linux box. :-) )
So, with all of that, I am in the process of testing different functionalities. The desire is to have a set of virtual workstations that I can push to the thin clients and that support streaming video, bi-directional audio, memory-intensive applications, and all of this with as minimal network impact as possible. I will discuss the overall evaluation results later in this post, or at a later date. :-)
Now back to the Windows 7 installation problem. The error message that I recieved:
"A required CD/DVD drive device driver is missing. If you have a driver floppy disk, DC, DVD, or USB flash drive, please insert it now."
is an artifact of the type of CD/DVD drives and drivers that Windows 7 recognizes during install. This message will actually appear after files have started copying to the local hard drive. That said, this message can be returned to a user under more than one situation, making it a pain to troubleshoot.
If you research this error message, a lot of what you will find is that people automatically assume that it is a bad ISO file. While this could be true, this was not my problem as I was using a disk, not an ISO. However, it may be good to list some of the reasons for this message, and how I determined that they did or did not apply. If you are reading this and just looking for the fix...scroll down further. :-)
Some Causes of the Error Message:
1) Trying to install from a corrupt ISO file.
- This did not apply to me as I was loading from a DVD. However, I will acknowledge that I re-downloaded the ISO and re-burned the DVD a second time just to rule out a bad ISO, and number 2 below.
- If you are using an ISO, there are some things you can do to verify that it is comoplete and not corrupt: Check the Hash value of the ISO, Check the size of the ISO, and do this against the listed Hash and Size values from your download site.
2) A Faulty DVD.
- While this was possible in my case, I ruled it out (See number 1 above).
3) A bad CD/DVD Driver on the host system.
- One would think that this would be the biggest culprit, given the error message. However, the biggest solution found on the net is number 1 above.
- This was in part my problem. When I installed the ESX Server, I didn't give much thought to drivers for hardware as I really didn't know at the time how far I was going with the server itself. Bottom line here is that I need to find a Windows 7 "approved" CD/DVD Driver and install this on the ESX Server. As a side note here, the ESX Server runs on a Linux Kernel (the exact version escapes me right now).
4) A bad CD/DVD Driver on the virtual system.
- This was in fact the other part of my problem. Contrary to popular belief, VMWare vSphere 4.0 is not "perfectly" compatible with Windows 7. In fact, as I may post later, there are some other issues that arose during this evaluation that were specifically related to the lack of complete OS support for Windows 7.
So, HOW did I fix this problem and create some virtual Windows 7 workstations????
I went the LONG way, on purpose (I'll explain in a bit).
THE FIX:
On a seperate machine on my network, I had already had a small virtual network setup inside a VMWare Server. Using this setup, and an ISO of Windows 7 Ultimate 32-Bit, I created two working virtual machines running Windows 7. Once I had created these two, it was a somewhat simple matter of getting the virtual "machine" onto the ESX server.
There are multiple options for transfering a virtual machine to an ESX server.
One option is to FTP directly to the ESX server and upload the virtual machine, and then run the VMWare converter tool. This is not the option that I chose. The ESX server does not come with FTP enabled by default and I did not feel like enabling FTP nor doing some of the things required for security compliance. For those curious, there is an RPM from VMWare for FTP, "vsftp," that can be used.
The method I chose took only slightly more work than FTP'ing directly to the ESX server. However, it was clean and worked. What I did was transfered the virtual machine folder (YES, the WHOLE FOLDER) to the Windows Server 2003 that contained my vCenter Server. After doing this, and I wish I had some screen shots, I logged into the vCenter Server itself using the vSphere Client. Once logged into the vCenter Server, I was able to browse the datastore that exists on the ESX server. Browsing the ESX Datastore through the vCenter server allows for the uploading of a file OR Folder. I obviously chose the folder. After the upload was complete, I browsed into the folder I just uploaded and selected the ".vmx" file. Right-clicking on this file will show the option to "Import this machine." After some conversion time, VOILA, my ESX Server now contained a working virtual machine using Windows 7 Ultimate.
I realize that this might not be the most optimum fix for long term issues requiring Windows 7 or Server 2008 R2. However, it was more important to prove that there was a method, other than FTP, that would allow me to create a virtual machine outside of the ESX Server, and them move it to the ESX Server.
The biggest issue that I had with creating the virtual Windows 7 boxes (AND Windows Server 2008 R2) was that I was getting this error message:
"A required CD/DVD drive device driver is missing. If you have a driver floppy disk, DC, DVD, or USB flash drive, please insert it now."
Before explaining the fix that I "found" for this error, I should probably include the other hardware and software I am working with for this little project:
- 1 ESX Server installed on a Penguin server
- 1 Penguin Desktop - Vista
- 2 Windows 2003 R2 Servers (one for the VMWare vSphere/vCenter Server, one for the VMWare Connection Server
- 1 IGEL Thin Client with both RDP (5 and 6.1) support and VMWare View Client installed.
- ALL VMWare software is at least release 4.0.0.
- Guests (Virtual) OS's
- XP 32-Bit
- XP 64-Bit
- Vista 32-Bit
- Vista 64-Bit
- Windows 7 32-Bit
- Windows 7 64-Bit
- Red Hat Enterprise Linux 5.1 (HAD to have at least one Linux box. :-) )
So, with all of that, I am in the process of testing different functionalities. The desire is to have a set of virtual workstations that I can push to the thin clients and that support streaming video, bi-directional audio, memory-intensive applications, and all of this with as minimal network impact as possible. I will discuss the overall evaluation results later in this post, or at a later date. :-)
Now back to the Windows 7 installation problem. The error message that I recieved:
"A required CD/DVD drive device driver is missing. If you have a driver floppy disk, DC, DVD, or USB flash drive, please insert it now."
is an artifact of the type of CD/DVD drives and drivers that Windows 7 recognizes during install. This message will actually appear after files have started copying to the local hard drive. That said, this message can be returned to a user under more than one situation, making it a pain to troubleshoot.
If you research this error message, a lot of what you will find is that people automatically assume that it is a bad ISO file. While this could be true, this was not my problem as I was using a disk, not an ISO. However, it may be good to list some of the reasons for this message, and how I determined that they did or did not apply. If you are reading this and just looking for the fix...scroll down further. :-)
Some Causes of the Error Message:
1) Trying to install from a corrupt ISO file.
- This did not apply to me as I was loading from a DVD. However, I will acknowledge that I re-downloaded the ISO and re-burned the DVD a second time just to rule out a bad ISO, and number 2 below.
- If you are using an ISO, there are some things you can do to verify that it is comoplete and not corrupt: Check the Hash value of the ISO, Check the size of the ISO, and do this against the listed Hash and Size values from your download site.
2) A Faulty DVD.
- While this was possible in my case, I ruled it out (See number 1 above).
3) A bad CD/DVD Driver on the host system.
- One would think that this would be the biggest culprit, given the error message. However, the biggest solution found on the net is number 1 above.
- This was in part my problem. When I installed the ESX Server, I didn't give much thought to drivers for hardware as I really didn't know at the time how far I was going with the server itself. Bottom line here is that I need to find a Windows 7 "approved" CD/DVD Driver and install this on the ESX Server. As a side note here, the ESX Server runs on a Linux Kernel (the exact version escapes me right now).
4) A bad CD/DVD Driver on the virtual system.
- This was in fact the other part of my problem. Contrary to popular belief, VMWare vSphere 4.0 is not "perfectly" compatible with Windows 7. In fact, as I may post later, there are some other issues that arose during this evaluation that were specifically related to the lack of complete OS support for Windows 7.
So, HOW did I fix this problem and create some virtual Windows 7 workstations????
I went the LONG way, on purpose (I'll explain in a bit).
THE FIX:
On a seperate machine on my network, I had already had a small virtual network setup inside a VMWare Server. Using this setup, and an ISO of Windows 7 Ultimate 32-Bit, I created two working virtual machines running Windows 7. Once I had created these two, it was a somewhat simple matter of getting the virtual "machine" onto the ESX server.
There are multiple options for transfering a virtual machine to an ESX server.
One option is to FTP directly to the ESX server and upload the virtual machine, and then run the VMWare converter tool. This is not the option that I chose. The ESX server does not come with FTP enabled by default and I did not feel like enabling FTP nor doing some of the things required for security compliance. For those curious, there is an RPM from VMWare for FTP, "vsftp," that can be used.
The method I chose took only slightly more work than FTP'ing directly to the ESX server. However, it was clean and worked. What I did was transfered the virtual machine folder (YES, the WHOLE FOLDER) to the Windows Server 2003 that contained my vCenter Server. After doing this, and I wish I had some screen shots, I logged into the vCenter Server itself using the vSphere Client. Once logged into the vCenter Server, I was able to browse the datastore that exists on the ESX server. Browsing the ESX Datastore through the vCenter server allows for the uploading of a file OR Folder. I obviously chose the folder. After the upload was complete, I browsed into the folder I just uploaded and selected the ".vmx" file. Right-clicking on this file will show the option to "Import this machine." After some conversion time, VOILA, my ESX Server now contained a working virtual machine using Windows 7 Ultimate.
I realize that this might not be the most optimum fix for long term issues requiring Windows 7 or Server 2008 R2. However, it was more important to prove that there was a method, other than FTP, that would allow me to create a virtual machine outside of the ESX Server, and them move it to the ESX Server.
Sunday, April 25, 2010
XML Parsing and SOAP messages
For a recent project, I needed to create a Web Services Conversation Language (WSCL) document (actually, four of these) and then be able to use another Web Service acting as a conversation handler to parse this XML and verify the protocols contained in the WSCL doc. This proved to be a challenge and reminded me that I need to better learn XML parsing in Web Services.
When a Web Service is created in Visual Studio, the service can be launched in a browser window. This page will show you the service available as well as a link to the WSDL document, and comments on the namespace if it is set to the default URL of tempuri.org. The screenshot below shows an example of this page.
Clicking on a Service name will allow you test the functionality of the service. Here is where an important note is annotated. When testing the operation directly, the parameters used are sent using HTTP POST. However, when accessing the Web Service through another application/service, the parameters are passed using SOAP messages by default.
So why is this important you might ask? Something gets lost in translation with the differences between HTTP POST and SOAP messages. When attempting read an attribute from an XML element, one can use the XMLReader.GetAttribute() function. This function is overloaded to allow for example: an int parameter (the index value of the attribute) or a string value of the attribute's XName. So, when parsing an XML document, one way to do this (using Visual Studio 2008, C#) is with something similar to the following:
using (XmlReader reader = XmlReader.Create(url))
{
reader.Read();
reader.ReadToFollowing("DestinationInteraction");
reader.MoveToFirstAttribute();
StartOp = reader.GetAttribute("href");
reader.Close();
}
This block of code will create an XML reader object (reader) and will then move to first Element with a name value of "DestinationInteraction." The reader is then moved to the first attribute of the Element and then assigns to (string)StartOp the value of the "href" attribute. An example of the portion of the WSCL document that this is reading is:
Notice that this Element has no values, only an attribute of "href" that has the value "OPName." And this is where the fun begins.
Parsing the value of Elements in an XML document is generally very easy. A developer can code such that only the required Element(s) is accessed (reducing overhead), or can parse the entire document, storing needed values for the application. It's the parsing of attributes, specifically using an "int" as the parameter that presents a problem.
The bottom line is this:
When using HTTP POST the XMLReader.GetAttribute(int i) will work properly. However, when attempting to use the int parameter in a SOAP message, this failed for me every time, with either an out-of-bounds error message (attributes can be accessed like an array [0...n]) or an invalid parameter error message. Needless to say that this was very frustrating for me, especially since I spent a LOT of time on this only to realize that the easy answer was to use the string parameter.
Using XMLReader.GetAttribute(string s) function allows the operation to execute properly (as long as s is a valid XName of the attribute) in both HTTP POST actions and with SOAP messages.
Unfortunately, this was another thing on which I spent a LOT of time that I really didn't have. I was not able to determine the cause of the problem, although it is obviously something in the way the SOAP messages are being handled. I assume it's the way that the client side is parsing the SOAP message and believe that although the SOAP message passes the int parameter as an int, the client-side is most likely parsing the int and casting it to a string. I have finals this week and will be focused on that in my free time. However, as SOON as my finals are over, I plan to spend some time on this one as I really want to know what the failure mechanism was with this operation.
When a Web Service is created in Visual Studio, the service can be launched in a browser window. This page will show you the service available as well as a link to the WSDL document, and comments on the namespace if it is set to the default URL of tempuri.org. The screenshot below shows an example of this page.
Clicking on a Service name will allow you test the functionality of the service. Here is where an important note is annotated. When testing the operation directly, the parameters used are sent using HTTP POST. However, when accessing the Web Service through another application/service, the parameters are passed using SOAP messages by default.
So why is this important you might ask? Something gets lost in translation with the differences between HTTP POST and SOAP messages. When attempting read an attribute from an XML element, one can use the XMLReader.GetAttribute() function. This function is overloaded to allow for example: an int parameter (the index value of the attribute) or a string value of the attribute's XName. So, when parsing an XML document, one way to do this (using Visual Studio 2008, C#) is with something similar to the following:
using (XmlReader reader = XmlReader.Create(url))
{
reader.Read();
reader.ReadToFollowing("DestinationInteraction");
reader.MoveToFirstAttribute();
StartOp = reader.GetAttribute("href");
reader.Close();
}
This block of code will create an XML reader object (reader) and will then move to first Element with a name value of "DestinationInteraction." The reader is then moved to the first attribute of the Element and then assigns to (string)StartOp the value of the "href" attribute. An example of the portion of the WSCL document that this is reading is:
Notice that this Element has no values, only an attribute of "href" that has the value "OPName." And this is where the fun begins.
Parsing the value of Elements in an XML document is generally very easy. A developer can code such that only the required Element(s) is accessed (reducing overhead), or can parse the entire document, storing needed values for the application. It's the parsing of attributes, specifically using an "int" as the parameter that presents a problem.
The bottom line is this:
When using HTTP POST the XMLReader.GetAttribute(int i) will work properly. However, when attempting to use the int parameter in a SOAP message, this failed for me every time, with either an out-of-bounds error message (attributes can be accessed like an array [0...n]) or an invalid parameter error message. Needless to say that this was very frustrating for me, especially since I spent a LOT of time on this only to realize that the easy answer was to use the string parameter.
Using XMLReader.GetAttribute(string s) function allows the operation to execute properly (as long as s is a valid XName of the attribute) in both HTTP POST actions and with SOAP messages.
Unfortunately, this was another thing on which I spent a LOT of time that I really didn't have. I was not able to determine the cause of the problem, although it is obviously something in the way the SOAP messages are being handled. I assume it's the way that the client side is parsing the SOAP message and believe that although the SOAP message passes the int parameter as an int, the client-side is most likely parsing the int and casting it to a string. I have finals this week and will be focused on that in my free time. However, as SOON as my finals are over, I plan to spend some time on this one as I really want to know what the failure mechanism was with this operation.
Making a Change and Who You Know
A few weeks ago(the week before the dreaded "Master's Week"), I received an odd email. This requires a little bit of back story, so I will do that before explaining the email and subsequent activites.
The back story:
When I was leaving the Army, I was contacted by a woman who works for the Georgia Department of Labor, Veterans Assistance. I was this woman's first client, and she really went the distance to help me find suitable employment in order to care for my family. It was obviously a stressful time (leaving the Army was medically forced due to a stupid surgeon, not by choice) and this woman really helped, and probably more than she even realizes. So with all of that said, I have still stayed in contact with her and have tried to pass on job information to her so that she may help other service members being medically discharged.
The email:
The woman I reference sent me an email asking if I was happy at my current job and if she could pass along my information to someone. Although I have been extrememly happy with my current job, I felt that out of respect for her, I would at least listen to what this other company was offering. This is where the "who you know" comes into play, in addition to being willing to take a chance.
The outcome:
I am starting a new job in a week. This new job is programming based, as opposed to network security. I am very, very excited about this new job as I have been wanting to be able to focus more on programming than just the occasional tool I build or the programs I write for school projects. Furthermore, since I AM working on my Master's in Software Engineering (from the University of Michigan!!!), I think that having more real-world experience is important and gives credence to my pending degree. The real dilema here is that I really do love my current job. If they could come close to what the new company has offered, I would stay. However, I don't think that that will happen.
In any event, it is a win-win for me. While I will miss my current job and the fun I have there, I am certain the new job will be just as fun, even though I KNOW it will be a huge challenge with a LOT of pressure to perform quickly.
My two biggest passions when comes to work are network security and programming. Now I will be changing focus to the programming and I know that the challenges this presents will be fun, if not a little stressful. :-)
The back story:
When I was leaving the Army, I was contacted by a woman who works for the Georgia Department of Labor, Veterans Assistance. I was this woman's first client, and she really went the distance to help me find suitable employment in order to care for my family. It was obviously a stressful time (leaving the Army was medically forced due to a stupid surgeon, not by choice) and this woman really helped, and probably more than she even realizes. So with all of that said, I have still stayed in contact with her and have tried to pass on job information to her so that she may help other service members being medically discharged.
The email:
The woman I reference sent me an email asking if I was happy at my current job and if she could pass along my information to someone. Although I have been extrememly happy with my current job, I felt that out of respect for her, I would at least listen to what this other company was offering. This is where the "who you know" comes into play, in addition to being willing to take a chance.
The outcome:
I am starting a new job in a week. This new job is programming based, as opposed to network security. I am very, very excited about this new job as I have been wanting to be able to focus more on programming than just the occasional tool I build or the programs I write for school projects. Furthermore, since I AM working on my Master's in Software Engineering (from the University of Michigan!!!), I think that having more real-world experience is important and gives credence to my pending degree. The real dilema here is that I really do love my current job. If they could come close to what the new company has offered, I would stay. However, I don't think that that will happen.
In any event, it is a win-win for me. While I will miss my current job and the fun I have there, I am certain the new job will be just as fun, even though I KNOW it will be a huge challenge with a LOT of pressure to perform quickly.
My two biggest passions when comes to work are network security and programming. Now I will be changing focus to the programming and I know that the challenges this presents will be fun, if not a little stressful. :-)
HTTP 404.8 ERROR
While working on a recent project involving web services, I started to get HTTP 404.8 errors, which I will discuss in a minute. The odd thing about this error is that it "just started." The project I was working on did not involve any "new" technology that I haven't already used on this box.
My current environment consists of:
- Windows 7 Pro
- Visual Studio 2008 Pro
- IIS 7.5
The HTTP 404.8 ERROR:
- Hidden Namespace. The requested URL is denied becuase the directory is hidden.
What does this mean???
This error is apparently returned when a directory is listed in the RequestFiltering/HiddenSegments of the applicationHost.config file for IIS. The fix for this is partially found at (http://support.microsoft.com/kb/942047). I say partially becuase it is still up to the user to determine which directory is the problem. However, I will still post the fix instructions here, with the caveat that this "might" not be the solution to everyone else's problem with this error.
Steps:
- Open Notepad as an Administrator (right click on Notepad, select "Run as administrator")
- Open the file named "%windir%\System32\inetsrv\config\applicationHost.config.
- Find the element and then the child tag
- Here's the annoying part...at least for me.
- In the section, find the directory that is causing you the problem. For me, it was the "App_Code" directory that had somehow become a problem.
The unanswered question here is: "What caused this error in the first place?" What was I doing when the error was returned? I was trying to use a Web Service instance in a project I was working on. This Web Service instance has been used in multiple projects and this 404.8 had never been returned before. In fact, when I recieved this error, I attemped to see if other Web Services I had recently created returned the same error when I tried to access them through my main application; the same error was in fact returned by all Web Services when accessed through the application, but not when I used the "View in browser" option for each service in VS2008. As frustrating as this was, I was under a serious time crunch to get the application working, and as such I have still not had time to properly research why this error started happening.
I do strongly believe the error to have been caused by some update to either Windows 7, IIS 7.5, or (even less likely) Visual Studio 2008. The update had to have been applied since the middle of February, as that is the last known time that the Web Service in question was successfully used. I may post a question to the forums on these, but it depends on time. Maybe somebody reading this can tell me why this error just "magically appeared" one day.
My current environment consists of:
- Windows 7 Pro
- Visual Studio 2008 Pro
- IIS 7.5
The HTTP 404.8 ERROR:
- Hidden Namespace. The requested URL is denied becuase the directory is hidden.
What does this mean???
This error is apparently returned when a directory is listed in the RequestFiltering/HiddenSegments of the applicationHost.config file for IIS. The fix for this is partially found at (http://support.microsoft.com/kb/942047). I say partially becuase it is still up to the user to determine which directory is the problem. However, I will still post the fix instructions here, with the caveat that this "might" not be the solution to everyone else's problem with this error.
Steps:
- Open Notepad as an Administrator (right click on Notepad, select "Run as administrator")
- Open the file named "%windir%\System32\inetsrv\config\applicationHost.config.
- Find the
- Here's the annoying part...at least for me.
- In the
The unanswered question here is: "What caused this error in the first place?" What was I doing when the error was returned? I was trying to use a Web Service instance in a project I was working on. This Web Service instance has been used in multiple projects and this 404.8 had never been returned before. In fact, when I recieved this error, I attemped to see if other Web Services I had recently created returned the same error when I tried to access them through my main application; the same error was in fact returned by all Web Services when accessed through the application, but not when I used the "View in browser" option for each service in VS2008. As frustrating as this was, I was under a serious time crunch to get the application working, and as such I have still not had time to properly research why this error started happening.
I do strongly believe the error to have been caused by some update to either Windows 7, IIS 7.5, or (even less likely) Visual Studio 2008. The update had to have been applied since the middle of February, as that is the last known time that the Web Service in question was successfully used. I may post a question to the forums on these, but it depends on time. Maybe somebody reading this can tell me why this error just "magically appeared" one day.
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