Scott's Weblog The weblog of an IT pro specializing in virtualization, networking, open source, and cloud computing

NFS Help

I like to think that I’m a fairly intelligent guy, able to pick up most things reasonably quickly given the opportunity. After all, I transitioned from a Windows-only SE into an SE with a good reputation for VMware ESX Server, various Linux flavors, Mac OS X, and some Cisco configuration (hey, if you can do GRE tunnels with IPSec encryption, you’re not too shabby with IOS). But I’m having a real problem with NFS.

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Statistically Secure

I’ll start out by saying that I am neither a security expert nor a statistician. With that disclaimer in hand, I wanted to briefly share my thoughts on the “days of risk” assessment that has recently been used to compare the security of Windows, Linux (Red Hat and SuSE), Mac OS X, and Sun Solaris. Before continuing, I encourage you to have a look at the actual report itself, along with a few related articles:

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Optimizing iSCSI Traffic with ESX

A response in this VMTN forums thread by Paul Lalonde got me to thinking about iSCSI traffic, network designs, and the software initiator provided with ESX Server. The statement was this (in response to questions about how ESX uses network links to communicate with an iSCSI storage array):

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Giving iTerm a Try

It invariably occurs that, regardless of whether I’m on a computer running Microsoft Windows Server 2003, some flavor of Linux or UNIX, or Mac OS X, I open a command prompt at some point or another during my session. I can’t really explain why; it’s just how I work. I find it faster to type ipconfig /all to get the networking configuration on a Windows box than right-clicking on My Network Places, selecting Properties, right-clicking the network connection, selecting Properties—you get the idea. I suppose it dates from my MS-DOS days, where I didn’t really have any other choice but to use the command line.

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Link State Tracking in Blade Deployments

It’s common in blade deployments to use multiple Ethernet switches in the blade chassis to provide network redundancy (I’ll refer to these as “in-chassis switches” moving forward). For example, in both the IBM BladeCenter H and the HP BladeSystem c-Class, we can provision multiple in-chassis switches so that half of the NICs on the blades connect to one in-chassis switch and the other half connect to the other switch. Within the OS, we load NIC teaming software to provide automatic failover if one of the links goes down. In this scenario, if one of the in-chassis switches fails then traffic will automatically fail over to the other switch.

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Cliff, I've Used VMware in Production

“How many people have deployed VMware or Xen or even Microsoft Virtual Server in a real production environment?” That’s the question Cliff Saran’s IT FUD blog asked yesterday. It’s an interesting question to ask an engineer such as myself who specializes in VMware deployments for customers. And while I can’t give out the names of some of my customers, I can tell you that more than a couple of them are using VMware Virtual Infrastructure 3 in production environments right now.

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More on CPU Masking

I just added another server to my VMware ESX Server farm, and since this farm is being built from leftover, donated servers that aren’t being used elsewhere (such is the curse for a non-revenue generating test environment), I don’t have the luxury of ensuring that all the servers in the farm have the same (or compatible) CPU families. As I’ve discussed in earlier blog postings (Sneaking Around VMotion Limitations and VMotion Compatibility), we can use custom CPU masks to help address the issue of different CPUs in the same ESX server farm.

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Moving ESX Into Firmware

The rumor that a slimmed down version of ESX Server, supposedly called “ESX Lite,” is being developed for placement into a server’s firmware, is circulating the Internet (see here or here). Most of these reports link back to a story on SearchServerVirtualization which quotes sources close to VMware stating:

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Leaving ESX for Virtual Server?

According to this article, cost and configuration issues are spurring at least one organization to ditch VMware ESX Server for Microsoft Virtual Server. Here’s a quote from the article:

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Cisco Link Aggregation and NetApp VIFs

Network Appliance storage systems support the use of virtual interfaces (VIFs) to provide link redundancy and improved network throughput. Two types of VIFs are available:

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