Question about upgrading from ESXi 4.1 and USB drives

[sofakng]

Right now I'm running ESXi 4.1 from a USB drive (ie. a very small thumb drive).

If I want to "start fresh" and use a newer USB drive for ESXi 5 but keep my guest operating systems intact, is this possible?  (For example, if I install ESXi 5.0 to a blank USB drive, will I be able to import my existing ESXi 4.1 operating system vmx images, etc?)

Also, what is the disadvantage of running ESXi 5 from a USB drive?  I'm running this in a home lab and have read that ESXi basically loads itself into memory upon booting so really the ESXi drive itself is pointless and a USB drive is perfectly fine.  Is this true?

[Dave_Mishchenko]

You can install ESXi 5 onto another USB key and then boot your existing host with it.  You'll need to setup your networking / storage / etc config again.

If you're using local storage the datastore should be visible.  You'll then have to browse the datastore and add your VMs to the inventory of your "new" host.

If you choose to upgrade the virtual hardware for VMs or to upgrade the datastore version then you won't be able to revert back to ESXi 4 (unless you have backups of the VMs elsewhere).  You can upgrade VMware tools and then downgrade back to ESXi 4 no problem.

[sofakng]

Thanks for the fast reply!

Is there any speed disadvantage to running off a USB stick?

[Dave_Mishchenko]

No, as you've noted once ESXi boots it is mainly dealing with a RAM disk.  With ESXi 5 you can run completely stateless, or install to a USB or HD device.  USB may represent a single point of failure, but it would be a rare occurence.

[terabyteit · Accepted solution]

If you don't want to re-configure ESXi 5.0 you can do the following:

1. Use free software called "USB Image Tool 1.57" to make an image of your 4.1 USB - software available here http://www.alexpage.de/usb-image-tool/ .  This way you can restore it to any USB in future.
2. After you have made a backup image of your 4.1 USB, upgrade the 4.1 installation to 5.0.
3. Make a backup of your ESXi configuration using vMA or vSphere CLI tool in Windows with the following command: vicfg-cfgbackup -save -server <yourESXiIPaddress> <NameOfConfigBackup.bak>
4. Perform fresh install of ESXi 5.0 on new USB
5. Use vMA or vSphere CLI tool in Windows with the following command to restore config backup from step 3: vicfg-cfgbackup -load -server <yourESXiIPaddress> <NameOfConfigBackup.bak>
6. You should now have ESXi 5.0 working on a new USB without any configuration required

You can also restore the USB image created in step 1 to your old USB so you have a 4.1 installation handy...

I would recommend you make a USB image of your 5.0 USB as well just incase the USB fails in the future.

[sofakng]

Thanks for all of the help!

I was wondering if a USB imaging tool existed so the information you gave me is perfect!

Thanks so much!