vSphere ESXi upgrade is really slow (About to install…)

During the past hours we upgraded our HPE blades from ESXi 6.0.0 U1 to 6.0.0 U2. During the process (using the vSphere Update Manager), the ESXi seems to be frozen on the step “About to install…”.


After 30 minutes we restarted all blades with this message thinking they were crashed/stuck… It’s been an error. The process wasn’t stuck, but only really really really slow. Perhaps it was specific to this version or to the HPE custom ISO (read comments, many users have problem with various hardware), I don’t remember this problem before.

So if you’re seeing the same problem you can solve it by being patient… simply. The install will end after 35/40 minutes. I wrote this post because I noticed on other blogs than the process wasn’t working and you need to install the upgrade manually. In our case, it was wrong, just being patient.

26 Replies to “vSphere ESXi upgrade is really slow (About to install…)”

  1. Hey
    Same problem here on my HP Blade center 460 G9
    after 45 min my setup has finished, it is HP bug

  2. Hey! Thanks for your blog post, was really helpful… in the same situation upgrading some DL580s from 5.5 to 6.0U2 Didn’t think it would be this slow but appreciate the heads up

  3. Hi there!
    Doing a ESXi 6 install on a brand new HPE ML110 G9 and the same thing happened. I will wait a bit. If it works I will come back here to tell the end of this story 🙁

  4. I came across this site because I had a similar issue on a Cisco UCS rackmount server (upgrade from ESXi 6.0 to 6.5 via Update Manager, and the whole process got stuck on “About to install” for a long time).

    After about 15-20 minutes, it has (finally!) moved on.

    So it seems to be less about server vendors, and more about vSphere being extremely slow to upgrade 🙂

  5. To top it off.. a tail from a home user.

    On Intel NUC NUC5i7RYH – Core i7, running ESXi 6.0, upgrade to 6.5, takes around 35-40 minutes, and then it’s only to tell me, that the image profile can’t be found.

    Yay ESXi upgrades! 🙂

  6. It’s been 24 hours for me, and still stuck at “About to Install”. I don’t think patience is going to help me here…

  7. Thanks for posting this, it was very helpful. Upgrade from 6.0 to 6.5.0d on a Dell R630 took about an hour on the About to install status but it finally finished.

  8. Whiskey Papa on 03/03/2017 at 15:01 said:
    It’s been 24 hours for me, and still stuck at “About to Install”. I don’t think patience is going to help me here…

    If you are trying to upgrade the Host from ESXi 6.0.0 u3 (Build:5224934)
    to ESXi 6.5.0, this is not compatible until VMware releases ESXi 6.5.0 u1 which is expected Q2 2017. Please see below Product Interoperability Matrices:

  9. Issue is related, at least in our case, to RDMs attached to the host profile. If your server can see RDMs, it tries to scan them, even during an install to a local hard drive. In a system with 10 RDMs used in an MSCS cluster with two nodes, a restart of the ESXi/ESX host with the secondary node takes approximately 30 minutes. In a system with less RDMs, the restart time is less. For example, if only three RDMs are used, the restart time is approximately 10 minutes.

    • Yep, same issue here. Our RDM’s are big. It takes an hour and a half to upgrade 1 host. No way around it sadly. Had an issue whereas they were set to persistent and caused it to go a lot longer. I wish VMWare would find a way to bypass scanning RDM’s during an upgrade….

  10. Getting this same problem on Cisco UCS blade hardware for host. Gets to “About to install…” but then flickers to a screen with a bunch of jibberish briefly before returning back to the loading screen.

    Hitting Alt+F12 shows some info, but whenever the system flickers, it returns you back to the loading screen – FRUSTRATING.

    I’m going to attempt to temporarily un-present the RDM LUNs on this server and see if that helps.

    • Hello MadMonk,
      I have the same problem with 6.5 installation on CISCO Blade servers, did you find any solution for it?

  11. Same issue upgrading a HPE BL460 Gen 9 to the ESXi build 6.5 U1. Console would show “About to Install” then the screen would flash then it would go back to the “About to Install” screen. To get around the problem I disconnected the fiber is virtual connect. I have multiple shared RDM in this environment.

    • I ran into the same issue on a Dell PowerEdge R730. I pulled the fiber connecting it to our storage. That resolved the issue for me.

  12. I’ve having the same issue on 6.5U2B on Cisco UCS. Waited almost 24 hours. Nothing. We do use RDM’s in our environment, but I just upgraded our entire other datacenter (that also see’s RDM’s) without an issue. It seems that we should have a work around to skip those RDM’s during the install process…

Leave a Reply to Florent B. Cancel reply

Your email address will not be published. Required fields are marked *