The v-Front Challenge #1: Solution and winners

A few days ago the V-Front Challenge #1 ended, and in the meantime I informed all the winners by e-mail. A big thanks to Trainsignal for sponsoring the prizes and to all who participated (I hope you had fun even if you are not a winner). Congratulations go to the winners of the raffle: Nikki R., Kelly M. and Johan! They receive a 30-days free training certificate from Trainsignal.

But the real challenge was the quiz part with the following question:

If you carefully look at the ESXi patch bundle that updates an ESXi 5.x host to ESXi 5.1 U1 then you will notice that its size is 610.2 MB. However, the installation ISO of ESXi 5.1 U1 is only 305 MB in size.
How do you explain this?

And these were the possible answers:

1. The ISO does not contain the full ESXi system, but only updated packages. So it can only be used to update an existing ESXi 5.1 installation, whereas the patch bundle really includes all system packages of 5.1 and can also be used to update an ESXi 5.0 host.

No, that is not correct. Both the ISO file and the patch bundle include all packages that make up an ESXi 5.1 system and can both be used to update also an existing ESXi 5.0 system.

2. Both the patch bundle and the ISO do really contain the same set of packages, but the installation ISO uses a highly efficient VMware proprietary compression technology, whereas the patch bundle uses regular zip compression only.
This is also incorrect. Neither do both the ISO file and the patch bundle contain exactly the same set of packages, nor does the ISO file use a special compression technology.

3. In addition to the official publicly available packages (that are in the ISO file) the patch bundle includes some private hotfixes that are to be used by certain Enterprise customers only. They can be selected for installation by using undocumented advanced options in Update Manager.
No, not really ... There are no hidden gems in the patch bundle.

4. None of the above statements is true. Please supply your own detailed explanation:

Sure, you had to do this ... and the first prize - the "Avoid the Zombie Apocalypse IT Survival Kit" plus a 30-days free training certificate - went to the one that gave the most precise and comprehensive answer here: Congratulations to Matt P.! And here is what he answered:

"The answer can be found in your November 6, 2012 blog entry entitled "Are ESXi 5.x patches cumulative?" The installation ISO contains 65 VMware Installation Bundles, including the base system and VMware tools, with most of the rest being hardware device drivers. The patch bundles contain not only the updated VIBs, but every VIB (all 65) that come with the original base system. So, you would assume that the patch bundle would at least be similar in size to the installation ISO. However, VMware very clearly distinguishes between security related updates and updates that are only functional-item related. Because they make this distinction, the patch bundles include two different copies of the VIBs, one copy which contains only security related fixes while the second copy contains both security and functional items. This distinction allows the customer to choose to update only security related items or update both security and functional items. This flexibility results in 130 VIBs in the patch package, doubling it's size. And I learned all of this from reading the blog on vFront!"

Great explanation! - there is only one small correction that I need to make: The patch bundle does not include two copies of all 65 VIBs, but only of the VIBs esx-base, tools-light, ipmi-ipmi-si-drv, misc-drivers, net-bnx2, net-e100e, net-igb, net-ixgbe, net-tg3 and scsi-megaraid-sas, because these were the VIBs that had functional patches added. All other VIBs had either only security patches added (esx-xserver and net-bnx2x) or were not modified at all since the last patch release.

However, because the esx-base and tools-light VIBs make up >95% of the size of all VIBs, the patch bundle nearly doubles its size.

My ESXi 5.x Patch Matrix is a detailed overview about what VIBs are included with each patch bundle, and there you will also see if a patch bundle includes a "security-only" image profile and - if yes - how it differs from the "all-patches" image profile.
By the way, the ESXi 5.1 U1 installation ISO (like all ESXi installation ISOs) includes only the "all-patches" image profile. This is why it's only 305 MB in size, but this also means that you won't be able to update an existing system with security-patches only when using a VMware supplied installation ISO file.

I hope that this makes it all clear, and that you found this challenge a fun way to learn something new!

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