Posts

Many times I see new virtualization admins add too many vCPUs to virtual machines after they’ve converted their physical machines. I believe the reason for this is a simple misunderstanding that more is not always better in this case. With physical servers, the more is better approach seems to work fine. If you have a quad core processor it’s better than a dual core and if you have a dual processor server it’s better than a single socket. When it comes to virtual machines extra processors can actually make a VM perform worse than having too few processors. ...

I decided to check out the new HP Performance Viewer and found it to be pretty useful. The appliance comes as an OVF so it’s great for importing into your vSphere environment. Once it’s installed you can go to the management URL and all you have to do is provide the name of the vCenter and login credentials. That’s all for the configuration! At this point I’d give the appliance some time to gather statistics, but if you just can’t wait I’ll give you some of the details from my install. ...

I recently took the VCAP5 - DCD exam and wanted to share my experience for anyone who is preparing for this exam as well. Study In my opinion this is a fairly difficult exam to do any sort of preparation for. Most of my preparation was just every day design that I’ve acquired over the years. I think the biggest trick for a lot of administrators is to switch from a mode of thinking about things in a breakfix method, but rather as a holistic design methodology. I prefer to look at a design as a “pie in the sky” approach where I put all the best solutions I can come up with to meet a design requirement, and then start to modify those based on any constraints that might be known. ...

I used to love the fact that with my old Netapp FAS2040 that I’d get a phone call about replacing a failed drive almost before I received the alert about the drive in the first place. Phone home seemed genius to me and as it turns out, Hewlett Packard has this capability for their equipment. Full disclosure: As many of you know, I currently work for an HP Partner so my advice may be a bit biased. I can tell you that I wouldn’t put a product on this site which I didn’t like so please don’t think that I’m just trying to push HP products. You may see more HP related articles from me, only because I encounter them more frequently than others. ...

In my last post I explained a memory reclamation technique called Transparent Page Sharing. This post is dedicated to the Balloon driver method. The first thing to be clear about is that Memory Ballooning is a technique that is only engaged when the host is running low on physical memory. If you have a host with 60 GB of physical memory available and the virtual machines are only allocated a total of 30GB of memory, then you may never need to know what memory ballooning is all about. However if you are over committing your hosts then this is an important topic to review. ...

One of the companies I worked for got a Netapp filer and I loved the fact that it would dedupe the data that was sitting on disk. I got over 40% more storage just by having that sweet little feature on. I was thinking, “How awesome would it be to dedupe my memory?” Getting more memory out of my servers would be a nice thing. Well as it turns out, VMware does this already, but they call it “Transparent Page Sharing.” ...

Jumbo frames can be useful to optimize IP networks, especially in storage networking. This post should help to explain why using jumbo frames can be useful. I’m not Jumbo, I’m just big boned! First, let’s define what we mean by the term jumbo frame. As you can imagine it’s bigger than a normal frame. A Jumbo frame simply means any frame with an MTU larger than 1500 bytes. What exactly does that mean? To really understand that we need to look at an Ethernet frame. The diagram below shows a hastily thrown together Ethernet frame and most of the frame we’re not concerned with for this topic. Parts of the frame are used for determining where the frame is headed, where it came from and to make sure it arrived intact. The section we’re looking at is the “Data” or “Payload” section of the frame. ...

HP Enterprise class storage has just entered the mid range market. Today HP announced the HP 3PAR StoreServ 7000 class which includes two devices; the HP 3PAR 7200 and the HP 3PAR 7400. The 7200 starts at $25k for the 2U device and the 7400 (seen below) is less than $40K for a 4U device. I’m very excited about this announcement because now HP has a storage device with the features that everybody wants and it’s now affordable for a smaller sized organization. HP has seemingly targeted one of it’s own devices with this announcement (the HP EVA) since it has been very popular with the mid-range business. They’ve even included some tools to migrate data from the EVA to the new 3PAR. I seriously doubt that the EVA will entirely go away, but the new big brother is going to steal some of their thunder. ...

When you team NICs together in ESXi 5 you can pick from a variety of load balancing techniques to determine how traffic should flow over the adapters. You might think that setting up software iSCSI initiators in ESXi would be done in a similar manner. Add a VMkernel to a vSwitch, add a couple of adapters and set a teamingfailover policy. It turns out that this is not the case. You could setup a software iSCSI initiator this way, but it won’t provide you the teaming or failover you’ve intended. ...

I just found out that I’ve passed the VMware Certified Advanced Professional 5 - Datacenter Administration exam and wanted to share my experience. When I first set out to take on this exam, I was apprehensive about it because of the number of possible questions that could be asked on it. The blueprint was quite large and covered basically everything related to vSphere. I got some helpful advice from a friend who told me that instead of worrying about if I could pass the exam, think about it like vSphere Olympics. It’s a chance to show off how much you know. It was a subtle change, but a different mindset really helped me. ...