VMware

Building an iSCSI SAN for VMware for Under $300

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In recent months, I’ve been assembling a lab to provide a test-bed for various network and infrastructure applications. My current role at Dell often involves multi-vendor networks, so having an easily accessible test bed including Cisco, Dell, Juniper and HP devices can be very useful for interoperability troubleshooting such as Spanning Tree Protocol.

I wanted to provide a robust virtual infrastructure, and in my experience that usually means VMware. I’m fortunate enough to have extra ESX Enterprise and Plus licenses from VMware partner registration. To utilize all the most useful VMware features like Vmotion and HA, a shared storage system is required. In addition, I wanted to incorporate as many iSCSI “best practices” such as using dedicated infrastructure, dedicated VLAN and Jumbo Frames without breaking the bank.

Without an extra $1-2 K on hand to go out and purchase a full-blown iSCSI SAN such as EqualLogic or Compellent (shameless Dell plugs), and already having a home NAS set up, my goal was to assemble a SAN utilizing as much extra or existing hardware as possible and of course limiting new expenses.

For my purposes, performance took precedence over storage capacity, and redundancy was not as important as keeping costs down (and streamlining design).

Ingredients:

Configuration:

  • I was able to re-purpose an unused PC for the iSCSI Starwind server, w/dual core CPU, 3 GB RAM, and Windows 7 Home. Starwind Free Edition doesn’t require a server OS so that was helpful.
  • The Intel GigE NIC was installed into the PC for a dedicated NIC to the iSCSI network, separate from the LOM.
  • The SSD was installed into the spare PC, and presented as a new iSCSI device.
  • I thought I had a 9 pin F-F cable already but didn’t…not common these days, anyway got lucky finding the last one in stock at Fry’s 🙂

Caveats:

  • For the SAN server, ideally this should be a Windows or Linux server O/S, however my hardware was more than adequate.
  • Starwind is a good option for Windows users, OpenNAS is an option for Linux folks.
  • JUMBO FRAMES are a MUST!! Jumbo Frames must be enabled end to end for optimal performance, and must be supported on the physical switch for starters. In addition, you’ll need to update VMware components for Jumbo frame support including vSwitch, port group, VMkernel, and guest OS NIC adapter. Here’s a great article on configuration for VSphere 4.
  • It’s always a good practice to create a separate VLAN for iSCSI as well.
  • LAN cables not included

Results:

  • I’m very pleased with my new iSCSI-based shared storage system, supporting VSphere 4 on (2) Dell SC1425 64-bit 1U servers. Responsiveness is snappy within VI Client, as well as within RDP for Windows guest VM’s.
  • VMotions on shared storage: 20-30 seconds, not bad compared to Enterprise-class SAN’s which I’ve observed at 10-20 seconds.

Here are my two Dell SC1425 servers, each with (2) 3 Ghz Xeon CPU’s and 6GB RAM, with dedicated 1 GB NIC’s for the iSCSI network.

No more Ubuntu desktop headaches

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After an ambitious nearly two-year project to work daily on an open-source desktop platform of Ubuntu with the standard assortment of apps such as OpenOffice, Evolution, GIMP, Virtualbox, and Brasero, am throwing in the towel after a botched upgrade of 8.04 Hardy LTS to Intrepid 8.10.

This was possibly the WORST upgrade experience imaginable, reminding me of XP -> Vista horror stories, and back to Windows NT 4.0 Service Pack 4. There is absolutely nothing that has improved following the upgrade, with the exception of slightly improved system responsiveness at the expense of strange delays such as attaching files in Firefox, in addition to the substantial time investment in researching new problems.

Following the standard recommended Ubuntu upgrade procedure, upon first reboot I got dreaded “read-only file system” messages that were only resolved by yet another strange Linux hack that modified the boot list.

Here are my Ubuntu desktop-related headaches which I about to leave for good:

  • A nagging Virtualbox error every time I launched my Windows XP VM. Many attempts to resolve the error were fruitless, meaning I have to enter a command manually after each reboot.
  • Non-functioning synchronization between Evolution and my BlackBerry. There’s too much hack-ery involved to get this to work. Plus, Evolution is plain Ugly, sorry kids-
  • Shaky dual-monitor support, mainly hesitance to mess up the dreaded “xorg.conf” file
  • Inconsistent support for Korean Hangul characters. Have to admit I underestimated the relative ease of East Asian language setup in Windows, which I’ve done for many family members. How is it that a document in OpenOffice displays Hangul, but the printer spits out nonsense??

But finally, I had managed to live with these drawbacks content in the labor of love participating in the open-source desktop world, but for these additional issues after the recent upgrade-

  • Brasero DVD/CD burner stops working
  • USB drives and SD cards no longer mount automatically
  • Ridiculous 1-2 minute delay in attaching files in Firefox
  • Multimedia file support broken (again!)

After gawking recently when my client bragged about his OSX Snow Leopard desktop (with a gazillion windows open), and realizing the majority of my projects have required Windows-only client software such as VMware VI Client or Internet Explorer…I’ve realized it’s time for this experiment to come to a close. In the short term, I’m humbly returning to the default install of Windows Vista on my Dell Inspiron 1525 laptop, to be followed by testing of Windows 7 and then, who knows? Maybe it’s time for another look at the Mac…

I certainly have developed a more nuanced appreciation for the pros and cons of open-source software, and admit that the outlook for Linux desktop continues to look bleak. On the other hand, the gravity of the computing world continues to shift away from a desktop-centric environment, and I’ve certainly benefited from deeper experience with Linux that has only helped my overall IT skill-set. Just a few years I certainly would not have been able to deploy a raw install of Ubuntu Linux to support a full-blown Nagios/Cacti deployment for a major corporate client, so it’s onward and forward!

Nagios is the real deal for network and system monitoring

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I’ve been heavily focused with getting Nagios implemented in my new environment at IHOP. It was surprising to learn that an overall monitoring and alerting system was not in place yet, given the complexity and maturity of the infrastructure. I had some prior exposure to Nagios through testing a VMA, but this was my first full installation.

One of the best aspects of Nagios compared to proprietary platforms is that there is a very active open-source community, and often plugins have already been developed for your particular need. For instance, I deployed one of these SNMP plugins (check_snmp_env) to monitor our Cisco switches and devices, so now we receive alert notifications in the event of any Cisco hardware failure.

There is an issue I discovered with installing the otherwise excellent NSClient++ on Windows hosts. Be careful with installing on SQL Server 2005 servers, sometimes the client install causes MS DTC Service and then SQL Server to shut down. Other than that, the NSClient++ has been stable on our Windows 2003 and 2008 servers, both 32 bit and 64 bit machines, and VMware VM’s as well as physical servers.

One more thing, if you haven’t yet implemented SNMP in your network, you’ll probably want to plan on getting at least SNMPv2 set up on the Nagios server(s), network devices and, ideally, Windows and Linux hosts.

I should mention there is an extremely useful book titled “Nagios, 2nd Edition” which will help provide additional documentation and get you up and running quickly.

Reactions to VMware’s VSphere 4

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I was impressed with the VMware simulcast this morning announcing VSphere, the next iteration of their enterprise virtualization platform, dubbed the first “Cloud OS.” Having deployed and administered VMware products for several years, it’s exciting to see them continue to push the evolution of virtualization, which has now expanded from a single server up to multiple data centers.

It’s also becoming quite apparent that a loose alliance is coalescing between several of the established leaders in the infrastructure space. In particular, VMware continues to align with Cisco, whose recent unveiling of a “Unified Computing System” combined with VSphere offers the promise of a private “cloud in a box.” Other members of this confederation are Intel, whose recent Xeon 5500 Nehalem chip is tailored for VM loads, in addition to EMC, whose updated Symmetrix SAN is optimized for VMware and Microsoft Hyper-V support. Dell appears to be more closely aligned than HP, and has a better position in the SMB market.

And don’t count out Oracle / Sun, one of today’s VSphere demo’s featured Sunfire servers, and when Cisco CEO John Chambers left the stage to congratulate VMware’s lead engineering team, Sun racks were featured quite prominently.

So who’s not joining the party, yet?

Here’s my list –

  • HP – not seeing innovation, very quiet these days
  • IBM – passed on Sun, noticeably low-key at today’s VSphere event
  • Google – how long before they offer a full-blown Cloud service
  • Microsoft – no support for Hyper-V in VMware VSphere
  • Citrix – falling further behind, no support from EMC Symmetrix, or VSphere

The continued limited inter-operability between major virtualization vendors – VMware, Microsoft, Citrix – and subsequent “vendor lock-in” really makes me wonder about the feasibility and likelihood of a truly Open Cloud platform, given the symbiotic relationship between Virtualization and Cloud computing.

P.S. I still think Cisco should have picked up Sun…

First thoughts on Cisco United Computing Vision

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My first response to Cisco’s announcement today is measured skepticism. Cisco certainly plays a central role in most modern data centers, dominating arguably the most critical infrastructure component, the network. By consolidating network, compute, storage and virtualization systems, Cisco is essentially offering a “cloud in a box.” Aside from the obvious marketing angle of leverage the current excitement around the cloud, though, it seems that Cisco is realizing they need more to drive sales of the new Nexus enterprise switch platform. However, while VMware and Microsoft are natural partners for virtualization, I’m wary of Cisco’s initial venture into the compute space. After all, a handful of companies with names like IBM, Dell and HP already have substantial experience in delivering enterprise server solutions, and I noticed none of them were listed as partners in the Cisco announcement. This is certainly a stark illustration of the new balance of power in the infrastructure world, where hypervisors and VM’s are taking precedence over bare-metal servers. Very interesting…

Strange bedfellows – Microsoft and Red Hat partnership

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This announcement really caught my eye. Essentially, Microsoft and Red Hat have agreed to mutually support each other’s operating systems on their emerging virtualization platforms. Thus, Microsoft Hyper-V will support Red Hat Enterprise Linux (RHEL) 5, and Red Hat Enterprise virtualization will support Windows 2003, 2008 and so on. The timing of the announcement, last Monday February 16 which was a national holiday, was probably more than coincidental in order to lower the profile of the partnership. These two companies are not known to be friendly with each other, with Red Hat firmly established as the leading commercial vendor in the Linux market that competes fiercely with Microsoft’s Windows Server offerings. In fact, at SCaLE( Southern California Linux Conference) this past weekend, there was no mention or discussion of this announcement anywhere.

I recall testing an early release of Microsoft’s Virtual Server, the precursor to Hyper-V, several years ago and observing that the only non-Microsoft OS officially supported was SUSE Linux. Given that Red Hat and Ubuntu dominate the lion’s share of the Linux market, with SUSE a distant third, I was less than excited about Microsoft’s “cross-platform” support. Contrast this with VMware’s native support of Ubuntu, RHEL, OpenSUSE, in addition to Windows, Novell and Solaris. VMware’s competitors continue to maneuver for position, including Citrix recently offering the Xen hypervisor for free, along with enhanced coordination with Microsoft. But VMware is still leading the pack, and they’re not sitting still.

A Cloud of Questions

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This is officially my first WordPress blog. I’ve been blogging somewhat infrequently at IT Toolbox, however their security-related outage over the weekend among other things has convinced me it’s time to launch a full stand-alone blog. I’ll be exploring and discussing primarily IT infrastructure-related topics, ranging from newer technologies such as virtualization and cloud computing to more general issues around network and system management.

Without further ado, I’ve come to the realization that, following several recent conversations and articles I’ve read, the current buzz around “Cloud Computing” is raising as many questions as answers. To wit, there seem to be widespread assumptions that presume all this messy “infrastructure stuff” – from physical servers to network switches, routers, backup devices, firewalls, appliances all the way down to cabling – is magically going away so that developers, and by extension IT, can get back to focusing on the soft and chewy application stuff. Hate to be the spoiler, folks…but it just ain’t happening, not yet, maybe never. Here’s why…The physical layer will continue to comprise one of the most support-intensive areas for IT. Desktops giving way to laptops, giving way to netbooks and mobile devices, all becoming smaller and more portable – but it’s still hardware, and still prone to failure. Who will that user call when their wristwatch/semi-neurally embedded PC stops functioning? Likewise, on a broader network level, pushing the responsibility for hosting applications and data out into the “cloud” away from local servers and infrastructure will just make the upstream connection, including the circuit, firewall, caching devices, LAN switches, that much more critical. It seems that there could be more than a passing semblance between the ASP hype of the dot-com era and today’s Cloud. And yet there are bound to be different implications in the business IT versus consumer space.

I plan to explore the Cloud more comprehensively in this blog, and will be sharing my experiences with real-world examples such as Amazon’s EC2 and Microsoft Azure. Other major topics to be covered include IT infrastructure, virtualization, Green IT, data centers, and hosting.