how to recover from failure of a USB flash drive with ESXi?

[OrionManufactur]

I have ESXi 5.5 running on a 16GB USB flash drive.  The system itself has a RAID card and mirrored disks where all the VMs are stored, so it seems to me that one critical point of weakness is the flash drive itself.  If the flash drive running ESXi itself dies, is there a procedure to recover the VMs on the drives?  Or should I be keeping a backup of my flash drive as well?

[OrionManufactur]

Can I bump this?

I'm running VMware ESXi 5.5 (and 6.0) on my servers off of a SanDisk Cruzer Fit 16GB flash drive. The VMs are stored on a RAID array of internal physical drives on the server.

If that flash drive fails, I'm assuming my system will be inoperable.

Two questions:

1. How to restore the system to operation assuming the flash drive fails? If I reinstalled ESXi on a new identical thumb drive, would VMware automatically see the already-existing VMs on the server's internal hard drives? Or is the process for discovering the existing VMs relatively painless?
2. How can I maintain redundancy for my flash drive in case of failure? Can I have two flash drives connected and automatically backup / mirror the first drive to the second?

[narenotpp]

1. How to restore the system to operation assuming the flash drive fails? If I reinstalled ESXi on a new identical thumb drive, would VMware automatically see the already-existing VMs on the server's internal hard drives? Or is the process for discovering the existing VMs relatively painless?

If your flash drive fails, won't be a trouble as you have your VMs safe on separate datastore in locally attached storage drives. all you got to do is reinstall ESXi host, it will be happy to see existing VMFS datastore and browse that datastore where your VMs are stored, and re-reigster them in inventory.

also see following KB to do configuration backup of your ESXi OS as and when you make configuration changes so at the time of ESXi failure, you don't have to worry about re-configuarting it

VMware KB: Backing up and restoring ESXi configuration using the vSphere Command-Line Interface and vSphere PowerCLI

1. How can I maintain redundancy for my flash drive in case of failure? Can I have two flash drives connected and automatically backup / mirror the first drive to the second?

this might not be possible (I have never tried it myself) if you are using external flash drive, but let's say you have hardware from specific vendor giving that functionality like

DELL IDSDM http://www.dell.com/downloads/global/products/pedge/en/poweredge-idsdm-whitepaper-en.pdf

or any other vendor giving similar functionality then it's quite possible to mirror it. Otherwise best option is take config. backup using KB I have mentioned in first answer.