Our foray into thin clients (a.k.a. VDI) has been anything but organized and smoothe. However, we've finally made some headway on a path that I believe will get us to where we want to be. Where is that you may ask? (Or maybe not...) Well, either way, I'll tell you. BYOT, BYOD, or whatever you want to call the activity of having students and teachers bring their own technology to school for use seems to be the way for education. At least, that's where are the hoopla is for now!
I fully support the idea and think it will be a great way for schools to move into the digital content arena on a bigger scale than we have thus far, speaking of K-12. Universities have seen the advantage of reaching students far and wide and seem to have taken a hold of it sooner. My vision is for us to be able to offer to any student, any time, anywhere, with any device, the same resources that they can find in a lab or on a classroom computer. Even beyond that, having teachers and students alike creating content that is useful, educational and a good learning experience. To enable this, we have do to several things first.
1. Create a method for students/teachers to connect to the network wherever they may be.
2. Create a method for students/teachers to use THEIR devices on the school network.
3. Improve the wireless support in house to enable those methods to work.
We've taken a new approach and are currently testing (successfully so far) using Hyper V and Quest running on Cisco's blade servers. Now, it could be any server, but this will help us reduce energy cost and support. I hope. For the end device in the labs and classrooms will be using Wyse CL10 devices where we have a wired connection and either netbooks or student owned devices in wireless areas.
Our next concern is to improve our wireless offering so that we can meet the demand, create a signed certificate (SSL) to enable the web interface for the Hyper V system, and create an SSID that will force all non-school owned equipment to the VDI web page. In theory, the web page is working. I'm working with StartSSL to get a very cheap *.calallen.org SSL certificate for all our sites and we are also evaluating both Meraki and Meru wireless AP's. We currently have Cisco wireless, but the AP's that we own will not support more than 25 concurrent connections.
Tuesday, November 8, 2011
Friday, May 13, 2011
Battery Backup
We've recently had a rash of UPS problems that confused us for a while. We have frequent blackouts or brownouts (more than I noticed before I got into IT) and it has caused some interesting moments. Usually a UPS will allow us to go through these short energy spikes without issue. Since our phone systems and data systems obviously need energy, and the world stops when communications stop, we try to keep these systems running for 15 to 30 minutes without power supplied from the outside world.
After a few recent events, we've found that our mega UPS systems don't stay up for more than 10 minutes and will not return to normal operations after power returns. Shortly thereafter, a strong burning smell permeates the data closet. Under closer inspection we were alarmed to find that one or more battery packs are very hot to the touch! As we removed the battery packs we found that they have begun to expand and what seems to be a chemical reaction is occurring where they leak.
As we've removed these batteries and replaced them the system will go back to functioning normally. So what causes this? Apparently after 3 - 5 years of use UPS batteries are prone to losing their ability to hold a charge. Once they do not hold a charge the UPS continues to try to charge them up, causing a very dangerous situation to occur inside the battery. Some reports have been given where they actually start fires.
So what can you do to monitor or prevent this? It seems that there is little to be done other than monitor and replace your UPS systems that are within this time range. We've evaluating the prospect of putting in thermal sensors to alert us to a battery pack that is getting hot. It amazes me that the one system you purchase to protect your electronic investments can ultimately provide their demise.
(Update 16May2011: We have measured the tempurature on some of the failing batteries (like today's) at over 160 degrees. Please use caution when removing these battery packs as they weigh over 40 pounds, are very hot and most likely are leaking acidic liquid when in this state.)
After a few recent events, we've found that our mega UPS systems don't stay up for more than 10 minutes and will not return to normal operations after power returns. Shortly thereafter, a strong burning smell permeates the data closet. Under closer inspection we were alarmed to find that one or more battery packs are very hot to the touch! As we removed the battery packs we found that they have begun to expand and what seems to be a chemical reaction is occurring where they leak.
As we've removed these batteries and replaced them the system will go back to functioning normally. So what causes this? Apparently after 3 - 5 years of use UPS batteries are prone to losing their ability to hold a charge. Once they do not hold a charge the UPS continues to try to charge them up, causing a very dangerous situation to occur inside the battery. Some reports have been given where they actually start fires.
So what can you do to monitor or prevent this? It seems that there is little to be done other than monitor and replace your UPS systems that are within this time range. We've evaluating the prospect of putting in thermal sensors to alert us to a battery pack that is getting hot. It amazes me that the one system you purchase to protect your electronic investments can ultimately provide their demise.
(Update 16May2011: We have measured the tempurature on some of the failing batteries (like today's) at over 160 degrees. Please use caution when removing these battery packs as they weigh over 40 pounds, are very hot and most likely are leaking acidic liquid when in this state.)
VDI - Storage
One of the two main hardware considerations for any virtual desktop deployment is storage. While the virtual instances will need computing power on the server side, you'll also need to consider storage capacity for each instance running. Many popular virtual desktop packages prefer a SAN connected to the system rather than a NAS. What's the difference? Glad you asked! The basic difference between the two is a SAN (Storage Area Network) connects and appears to the server as local storage. Whether it is through iSCSI connections or fiber channel, the server acts and communicates as if the storage that is carved out is a physical disk or array. The SAN storage space can be expanded on the SAN controller. Speeds are generally better for a SAN than a NAS. Another word you'll want to research is IOPS. Go to a tech net article here on calculating iops or (input/output operations per second). The higher the IOPS the better the system.
A NAS is a Network Attached Storage device. It is a lot of hard drive space that you can utilize over the network. Obviously it will not have as good of read/write speed as a NAS, but can be much cheaper to purchase and support. Fiber channel switches are not cheap and iSCSI connections can be real fun if you don't know what you are doing. The VDI system we are using prefers a NAS. However, if it doesn't work out, the other systems we'd use prefer connecting to a SAN for performance.
So what to do? We went with NetApp precisely for this reason. NetApp can run either as a SAN or a NAS on the same box. So, while we might use the NAS side for virtual desktops, we can connect to the SAN side for other storage needs! We'll let you know how the installation and training goes and how difficult it is to manage. You can get an idea on NetApp's site for free as a guest user. This is only for a limited time.
A NAS is a Network Attached Storage device. It is a lot of hard drive space that you can utilize over the network. Obviously it will not have as good of read/write speed as a NAS, but can be much cheaper to purchase and support. Fiber channel switches are not cheap and iSCSI connections can be real fun if you don't know what you are doing. The VDI system we are using prefers a NAS. However, if it doesn't work out, the other systems we'd use prefer connecting to a SAN for performance.
So what to do? We went with NetApp precisely for this reason. NetApp can run either as a SAN or a NAS on the same box. So, while we might use the NAS side for virtual desktops, we can connect to the SAN side for other storage needs! We'll let you know how the installation and training goes and how difficult it is to manage. You can get an idea on NetApp's site for free as a guest user. This is only for a limited time.
Wednesday, April 27, 2011
VDI - Physcial Considerations
As we began to evaluate memory, cpu size and count, storage size, etc... we thought we had covered all the bases on our needs for our VDI solution. We were sure that no stone was left unturned in making sure that it would all be a great success as far as we could measure. Oops! As you look at your needs do not forget to look into rackspace needed as well as power requirements! Often overlooked until it is time to install, this can be quite a large expense added into your calculations of the cost of VDI or any other server installation.
Also, don't forget to look at cooling needed in an often already crowded an under cooled area. Fortunately for us we have 15 tons of A/C piped into our room that we had constructed last summer to ease the cooling needs. Most school data rooms in smaller and older buildings are put "wherever they fit" and often fall short of the requirements to keep your equipment running smoothely and longer.
Power sometimes can become an issue as some systems need more than just the normal 110 outlet and call for special twist-lock plugs similar to those found on household dryers. Have your electrician make sure that the circuit breaker panel can sustain the increased load of electricity and count of outlets that you'll need for the UPS systems required for your servers. Know that there will be power savings for blade systems, but they need a bigger "pipe" to power the whole system. Rackspace can be a concern as well as you can't spread the system out across several small spaces. The UPS system for our blade server alone will take up 24 units of measure on one rack. That is half the rack!
When planned out correctly, the virtual desktop solution will be a great cost savings in the long run. Just do not forget to calculate all the "start up" costs, including space, power and cooling.
Also, don't forget to look at cooling needed in an often already crowded an under cooled area. Fortunately for us we have 15 tons of A/C piped into our room that we had constructed last summer to ease the cooling needs. Most school data rooms in smaller and older buildings are put "wherever they fit" and often fall short of the requirements to keep your equipment running smoothely and longer.
Power sometimes can become an issue as some systems need more than just the normal 110 outlet and call for special twist-lock plugs similar to those found on household dryers. Have your electrician make sure that the circuit breaker panel can sustain the increased load of electricity and count of outlets that you'll need for the UPS systems required for your servers. Know that there will be power savings for blade systems, but they need a bigger "pipe" to power the whole system. Rackspace can be a concern as well as you can't spread the system out across several small spaces. The UPS system for our blade server alone will take up 24 units of measure on one rack. That is half the rack!
When planned out correctly, the virtual desktop solution will be a great cost savings in the long run. Just do not forget to calculate all the "start up" costs, including space, power and cooling.
Wednesday, April 20, 2011
VDI - The future of the classroom?
The move to online classes is not a new concept, but it is relatively new in the K - 12 arena. True, there are virtual high schools popping up all over the place, but to have your everyday teacher creating and using content for online instruction is still in the infancy stage. One particular problem is that of access. Older buildings were just not designed to accommodate classrooms full of computers. They don't fit, don't have the power or network connectivity that they need and are hard to make current. Wireless was thought to be the answer to that issue, on a limited basis. And truly, it is part of the solution. However, the cost to supply laptops for every classroom, manage the wireless connectivity, keep the buggers charged and maintained has been something just out of reach for all but the best equipped (and funded) school districts. Some have been able to do grade levels at a time, but they still haven't reached that critical time of replacement once the grant funded resources dry up, as they have been doing lately in the budget crisis days we live in.
So, how do we meet the growing need of online access to the growing wealth of content being created by companies and teachers alike? How will we manage to allow students to access content at school or at home anytime, anywhere? One possible solution that has presented itself is the Virtual Desktop. While most are familiar with virtual servers and their platforms, virtual desktops are a growing and expanding trend. traditional companies such as VMWare and Citrix are being joined by companies such as nComputing and Virtual Bridges (to name two) who are jumping into this new and exciting market. So, where do we go from here?
Truth be told, there is a great difference between Virtual Bridges and nComputing platforms and processes. nComputing is one of the more popular (at least in education) hardware/software packages that allow you to reutilize your existing pc processing power and extend that into thin clients (or dumb terminals) that are attached to a card in the host machine. The advantage is less power, lower cost per unit and easier management. If you are running 4 "extended" terminals off of one host you only have to update that one host. Of course, there are issues that sometimes arrive with this setup on certain programs that need to have exclusive access to certain folders if more than one user is on that program on the host machine at one time. Overall, it is a good solution to save money through less power usage and less hardware cost. (So good, in fact, that Microsoft made a licensing deal with nComputing for a peak at their code on how they do this.)
Another solution sold by nComputing allows the terminals to connect directly to the network and work off networked based hosts. This is relatively green still and working out bugs that arise on occasion with 100% CPU utilization. Obviously, for this and other networked based thin clients you'll want to make sure that your network is up to speed and without issues. Another potential downside is that since this deployment option (just like the pc connected version) only allows up to seven virtual connections to each host. Want 24 computers in a lab? You'll need roughly six hosts, whether virtual or physical. Need to update software? You'll have to do it six times. (Which really is a lot better than 24 times!)
Virtual Bridges (and it's similar cohorts such as Stoneware) utilize an approach similar to VMWare's Vue product. Hosting virtual desktops on servers allow you to update any and all dekstops from one convenient location. With "gold" images used for each session, you only need to create and update as many unique images as you need to host. Have a lab of 24, 48 or more computers that are just alike? Just update one image!
The piece that sets Virtual Bridges apart from VMWare or Citrix though is that they offer the virtual desktop through a browser based session. (They are also less expensive!) Need a 1 to 1 computing initiative but can't afford all the devices? Now, using your wireless infrastructure you can allow students or teachers to bring their own computing devices that have a browser and they too can have a school desktop! Little Johnny wants to work on his school project at home but doesn't have the school software? No problem! Log on to the virtual desktop and you're back in class! (At least in theory.)
We'll be implementing this particular solution this summer and trying it out in the 2011-2012 school year. Seeing how the State of Texas is pushing all districts to host online content and use online textbooks, maybe this will help pave the way!
While this will allow us to reduce energy costs by using dumb terminals in many locations (Samsung has an all in one we will be using for less than $450 and it only uses 1.5 watts for computer and monitor) we can also reuse any old machine that can run IE 8, or 9 or whatever version will be out next week. In theory we should see a reduction in support costs. However, to get here we had to spend considerable money up front (as opposed to long term PC replacement costs). The ROI shouldn't be more than three years, and could be faster. To enable this setup we will be using Cisco's new UCS blade server bundle and NetApp's NAS/SAN storage solution. The UCS server will have 8 blades with a mountain of processors and memory. And while this will take some massive energy connections it will still be less to power and cool than 8 individual servers. The NetApp solution will host 24 TB of storage space that we can expand over time as needed. It won't be all for virtualization at first as we plan to expand as we go. This leads us into another feature I like about Virtual Bridges. You license only concurrent sessions. So, just because we currently have 1500 devices in district right now, we won't necessarily need (right now) 1500 licenses since not all machines are used at once. As students and teachers bring their own devices though it will definitely expand.
I will follow our server, storage and software deployments over the summer to give you a close to play by play view of how everything installs and runs, what issues we encounter and if it all works as well as it is sold! Stay Tuned!
Bryan Brown is the Technology Director for Calallen ISD and has worked in that district since 2007. In that time the technology department has revamped the entire network with a 10 GB backbone, reduced the server needs through virtualization, implemented centralized wireless systems, IP video surveillance and a VoIP phone system. He has worked in the IT field for more than 10 years and has enjoyed working and consulting for businesses and schools alike.
So, how do we meet the growing need of online access to the growing wealth of content being created by companies and teachers alike? How will we manage to allow students to access content at school or at home anytime, anywhere? One possible solution that has presented itself is the Virtual Desktop. While most are familiar with virtual servers and their platforms, virtual desktops are a growing and expanding trend. traditional companies such as VMWare and Citrix are being joined by companies such as nComputing and Virtual Bridges (to name two) who are jumping into this new and exciting market. So, where do we go from here?
Truth be told, there is a great difference between Virtual Bridges and nComputing platforms and processes. nComputing is one of the more popular (at least in education) hardware/software packages that allow you to reutilize your existing pc processing power and extend that into thin clients (or dumb terminals) that are attached to a card in the host machine. The advantage is less power, lower cost per unit and easier management. If you are running 4 "extended" terminals off of one host you only have to update that one host. Of course, there are issues that sometimes arrive with this setup on certain programs that need to have exclusive access to certain folders if more than one user is on that program on the host machine at one time. Overall, it is a good solution to save money through less power usage and less hardware cost. (So good, in fact, that Microsoft made a licensing deal with nComputing for a peak at their code on how they do this.)
Another solution sold by nComputing allows the terminals to connect directly to the network and work off networked based hosts. This is relatively green still and working out bugs that arise on occasion with 100% CPU utilization. Obviously, for this and other networked based thin clients you'll want to make sure that your network is up to speed and without issues. Another potential downside is that since this deployment option (just like the pc connected version) only allows up to seven virtual connections to each host. Want 24 computers in a lab? You'll need roughly six hosts, whether virtual or physical. Need to update software? You'll have to do it six times. (Which really is a lot better than 24 times!)
Virtual Bridges (and it's similar cohorts such as Stoneware) utilize an approach similar to VMWare's Vue product. Hosting virtual desktops on servers allow you to update any and all dekstops from one convenient location. With "gold" images used for each session, you only need to create and update as many unique images as you need to host. Have a lab of 24, 48 or more computers that are just alike? Just update one image!
The piece that sets Virtual Bridges apart from VMWare or Citrix though is that they offer the virtual desktop through a browser based session. (They are also less expensive!) Need a 1 to 1 computing initiative but can't afford all the devices? Now, using your wireless infrastructure you can allow students or teachers to bring their own computing devices that have a browser and they too can have a school desktop! Little Johnny wants to work on his school project at home but doesn't have the school software? No problem! Log on to the virtual desktop and you're back in class! (At least in theory.)
We'll be implementing this particular solution this summer and trying it out in the 2011-2012 school year. Seeing how the State of Texas is pushing all districts to host online content and use online textbooks, maybe this will help pave the way!
While this will allow us to reduce energy costs by using dumb terminals in many locations (Samsung has an all in one we will be using for less than $450 and it only uses 1.5 watts for computer and monitor) we can also reuse any old machine that can run IE 8, or 9 or whatever version will be out next week. In theory we should see a reduction in support costs. However, to get here we had to spend considerable money up front (as opposed to long term PC replacement costs). The ROI shouldn't be more than three years, and could be faster. To enable this setup we will be using Cisco's new UCS blade server bundle and NetApp's NAS/SAN storage solution. The UCS server will have 8 blades with a mountain of processors and memory. And while this will take some massive energy connections it will still be less to power and cool than 8 individual servers. The NetApp solution will host 24 TB of storage space that we can expand over time as needed. It won't be all for virtualization at first as we plan to expand as we go. This leads us into another feature I like about Virtual Bridges. You license only concurrent sessions. So, just because we currently have 1500 devices in district right now, we won't necessarily need (right now) 1500 licenses since not all machines are used at once. As students and teachers bring their own devices though it will definitely expand.
I will follow our server, storage and software deployments over the summer to give you a close to play by play view of how everything installs and runs, what issues we encounter and if it all works as well as it is sold! Stay Tuned!
Bryan Brown is the Technology Director for Calallen ISD and has worked in that district since 2007. In that time the technology department has revamped the entire network with a 10 GB backbone, reduced the server needs through virtualization, implemented centralized wireless systems, IP video surveillance and a VoIP phone system. He has worked in the IT field for more than 10 years and has enjoyed working and consulting for businesses and schools alike.
Subscribe to:
Comments (Atom)
Posts
