What you’re seeing
- A yellow warning in the host summary reads "Bootbank cannot be found at path '/bootbank'".
- The host shows as not responding or disconnected in vCenter, although its VMs may keep running for a while.
- Patching, configuration changes and even saving settings fail, and changes are lost after a reboot.
- The host hangs on restart or cannot find its boot device at all.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- The SD card or USB stick holding ESXi has worn out, since these devices were never designed for constant writes.
- ESXi 7.0 writes far more data to the boot device than older releases, which accelerates failure on SD and USB media.
- A dual-SD module, such as Dell IDSDM or HPE dual microSD, has lost one or both cards.
- Logs, scratch space or VMware Tools images were left on the boot media instead of persistent storage.
- A driver or firmware issue with the USB or SD controller makes the boot device drop off the bus.
Why it matters
A host that has lost its boot device is running on borrowed time. It may keep VMs alive until the next reboot, power event or patch window, and then refuse to start, taking every workload on it offline. Because configuration changes are no longer saved, any fix applied in the meantime can vanish. VMware has stated that SD cards and USB sticks are deprecated as standalone boot media, so many small businesses are carrying this risk across several hosts at once without realizing it.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Our VMs are still running. Is this urgent?
It should be treated as urgent. The VMs stay up only until the host reboots, and if the boot device is truly gone the host may not come back on its own.
Do we need new hardware?
Usually only a reliable boot device, such as a small SSD or BOSS card, rather than a whole server. An engineer can confirm what fits your model.
Can someone help us plan the boot device replacement?
A certified US engineer assesses the host and plans a safe path back to a stable boot setup over a remote secure session. Work starts from $99 and you pay only when resolved.