VMWare vSphere and the move from ESX to ESXi

I was working on a standalone ESX 3.5 system last night in order to upgrade to vSphere 4.1u1. I realized that the full ESX download had been deemphasized on the VMWare website. While I've known that the focus in the VMWare world was moving towards ESXi, I now realize that I have to actually assess the impact that this will have on my existing deployments.

I'm a consultant and have a range of VMWare installations, ranging from single hosts with internal storage to multi-host clusters backed by shared storage. I've mainly relied on HP ProLiant hardware as well. For me, the main attraction of ESX over ESXi was the presence of the HP Management Agents and a console capable of running HP-specific utilities (firmware updates, ILO configuration, SNMP traps, etc.)

I am interested in hearing how other IT engineers are handling the transition. For those of you who've installed full ESX 4, are you migrating hosts as needed? Are you making a concerted effort to move to ESXi now or waiting until the next upgrade cycle?

Either way, what are some of the challenges, missing features, etc. that you've encountered in making the move from ESX to ESXi?

Solution 1:

First of all, let's get one very important, but simple thing out of the way. There will not be ESX 5. If you want to future-proof your deploments, you have no other choice but start using ESXi today.

However, I wouldn't push existing environments towards ESXi right now. By the time ESX 4.1 becomes obsolete, those environments would need to go through hw refresh anyway, and that would be the more appropriate moment for the move.

Now, let's talk about the difference in managing ESX and ESXi. It's true that having a proper rpm-based environment is a huge benefit for the sysadmin in many ways. To VMware and hw vencors' credit, however, I have found that most, if not all, tasks can be accomplished without a full-featured console. Let me break it down into major pieces:

• Console access: if you want the comfort and confidence of using command line on the actual ESXi host, you can easily do it today, just enable local console to use KVM or iLO or iDRAC, or turn on sshd for remote access. This gives you busybox plus the full gamut of esxcfg utilities.
• HW management: I worked with HP and Dell hw, and they both have VIBs that you install on the host and use with SIM or OMSA. Moreover, Dell now has Dell Management Center vApp/plugin that seamlessly integrates into vCenter. It monitors hosts and can automates provisioning new hosts. It's a very cool tool.
• ESXi management and automation: use PowerCLI, if you live in the Windows world, or vSphere SDK for Perl, if you prefer Linux. With these, you will never (or almost never) need host console. Every single esxcfg command exists there, and much, much more.

Working with internal storage probably becomes easier with ESXi, because your whole hypervisor and its management tools live on a flash card or USB stick, and you can have just a single partition using the whole physical disk or volume, dedicated to storing VMs.

Updated 5/21/11: VMware has just released ESXi 4.1 Operations Guide that covers everything in good detail:

Solution 2:

You probably want much more detail than this but I've had literally zero issues in dealing with ESXi, although my experience is entirely using fully licenced code and in vCenter-only environments. In these scenarios I've found it to be quick to deploy, easy to maintain, just as stable and of course there are less patches that need to be applied. This has been in an entirely HP environment with SIM 6.x and I've not had to install any extra code either. Again though I have to state that my experience has been very limited to these environments.