New testing environment for my users
September 2, 2009
If you are responsible for a production infrastructure where services are necessary around the clock and are required to be stable, chances are good that you’ve not only got a production environment, but that you’ve got a testing environment behind it. If you don’t, let me be the first to try to guide you in that direction.
Your production equipment is important. It’s necessary that it works, and you probably can’t take it down to try new things. This is why it’s vital to have an environment where you can try new things, and also where you can produce the next generation of your infrastructure when that time comes.
In our production environment, we’ve got a pretty wide array of services, internal and external, but the heart and soul of the processing and reporting system consists of three identical machines over which the load of the data-production is spread. Currently, our testing facility is one underpowered machine, and it has been limping along lately.
Today I took an older machine, a Dell PowerEdge 1950, which came with 4GB of RAM and a quad core 1.6ghz processor, and beefed it up a little…
That’s not the maximum that the machine can hold, but it is the most I had conveniently on hand. I’ve settled on VMware ESXi as a bare metal hypervisor for now. I’m not eliminating the thought of XEN, but I need to get this out the door, and sometimes what you know is more important than what is best, particularly when what you know is pretty close to what is best.
Once I’ve got the first virtual machine machine created, I’m going to clone it into two other VMs, so that it will much more closely resemble the production environment. With three machines, configured identically totheir production counterparts, our testing environment is about to get a serious upgrade.
Incidentally, I found that VMware ESXi doesn’t allow cloning virtual machines right out of the box. I researched a bit and found a couple of different techniques to accomplish the same thing.
I’ve got to say…working with the vsphere client is pretty nice. I like it the best of all the VMware interfaces I’ve seen so far. Once I get the hang of it, it’ll be much better, though. I still haven’t found all the nooks and crannies. Any tips and tricks are definitely welcome, as well as suggestions for general administration of ESXi hosts. I’m new to this whole thing.
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September 2nd, 2009 at 8:44 am
Careful, like Quakelive once you start it’s hard to stop. I think you’ll be very pleased and pleasantly surprised with ESXi. I’m guessing you’ll soon be thinking about moving off VMware Server (if you haven’t already) to ESXi. Ping me if you need any 2nd opinions on ESX stuff.
September 2nd, 2009 at 11:15 am
Indeed, once you start it’s hard to stop. I recently did demos for my group at $work comparing xenserver (from citrix), and ESXi. We voted and Xenserver won unanimously. Even without shared storage for the demo I was able to accomplish more with Xenserver than ESXi. Some of the things you get for free with Xenserver: multi host management from the gui, easy template creation, easy backups of virtual machines, live migration (if you have shared storage). Really the only thing you can not do at this point with Xenserver is over commit memory (which i freely admit would probably be beneficial in a development environment. I spoke with both vendors sales goons and vmware rubbed me wrong, more or less they just tried to slander Citrix (i dont find that sales tatic compelling).
Really both are great products. For me it came down to what could I do the most with for the least cost. Xenserver just seemed to fit the bill for me. So if you decide to give Xenserver another try feel free to ping me. Otherwise I will be interested to see how you deployment of ESXi goes.
September 2nd, 2009 at 12:09 pm
I don’t mean to proselytize, but we just finished migrating our four machine cluster of ESX 3.5 hosts to Xenserver. Suffice it to say we think it’s great, and anyone else who likes it will tell all about how awesome it is, but let me share some of the things about it that I dislike instead of the things I like.
First, it doesn’t exactly virtualize in the same sense that VMware does. There’s a fast (FAST) paravirtualized mode and a slow/generic mode (pretty slow), which I think uses QEMU, and if you’re migrating random linux machines from ESX, there’s a good chance you’ll end up in slow mode until you get a Xen kernel in there. You can install the citrix tools, which include that kernel, but it’s missing some important (for me) stuff like the cifs kernel module which I need for my backups. It can take a considerable amount of fiddling to get an ubuntu or debian host going, where on vmware, pretty much every reasonable choice of OS worked at a consistent rate of speed. This problem can be mitigated by use of the prebuilt templates or roll your own template. It’s fun to have a fully base-configged usable linux machine in 3 minutes.
The other thing is, we still don’t have the enterprise license. We intend to, but their resellers lack hustle. One of them even tried to talk/scare us into buying VMware again. What gives? If I were a salesperson who had a potential customer asking for a specific thing, I’d do my best to get them that specific thing ASAP. This particular guy had a list of vendors in his email signature starting with VMware and Citrix somewhere in the middle, so perhaps there’s a bias at work there.
I do like how simple XenServer is, including the support site, forums, licensing, all of that. But the simplicity can be deceptive. On my 5.0 to 5.5 upgrade, I botched it by upgrading the pool members first and then attempting to upgrade the pool master. There were problems because the versions were not in sync. The trick is to upgrade the master first, then the members. They have this master/slave design to avoid the need for a dedicated management server like virtualcenter.
The client is nice and simple but I’ve noticed two bugs. Sometimes it doesn’t close all the way. Firefox does this sometimes too. Maybe it’s got a file or socket or something open, but the UI’s closed and I have to kill the process to restart the client. And speaking of restarting the client, sometimes when switching the console driver in a linux guest, (something they really have over vmware — you can paste into the plain console) you’ll get a prompt, but keystrokes don’t go to the terminal. Restarting the client fixes that Both issues are fairly infrequent.
For some reason on windows guests the mapped virtual hard disks show up as removable devices. You can’t actually remove them, but this kind of wart looks bad on a terminal server where there’s an option to “Safely remove NETAPP LUN SCSI Disk Device – Drive(C:)”. Ugh. I wonder what posessed them to do it that way?
For us, the deciding factor was also cost. We’re paying, but paying less.
Also, you can get support on the free version for $400/incident. Some people don’t know this, so I thought it was worth mentioning.
September 2nd, 2009 at 1:46 pm
I administer our 21 host ESX cluster at $work and hold a VMware certification. In my biased opinion Xen and HyperV are playing catchup to VMware. Albeit, Xen is doing a much better job than Microsoft.
The only tip I have is to be careful when talking about virtualization. It is easy for management to think hardware is free, and customers to start making ridiculous requests because it only takes 15 minutes to set up a new virtual machine from a template when it takes multiple days to get real hardware racked, OS installed, and networks configured.
The VMware forums are full of hackers bending ESXi to do things it is not supposed to; i.e live migration, and online backups, all done with powershell scripting. Feel free to contact me if you have questions…
September 7th, 2009 at 5:04 pm
I’ve recently setup some ESXi servers at $work; enabling SSH is a must for easy use. The ghetto scripts (ghettovcb in particular) are very useful, and an NFS server works very well with it for a quick backup. It could also be used as a method of cloning, but you’d probably want to create fresh vmx files to avoid conflicts.