What you’re seeing
- VMs freeze and vSphere displays a question saying there is no more space for the virtual disk, asking whether to retry or cancel.
- The datastore shows 0 bytes, or very little, free space.
- Several VMs on the same storage stop responding at the same moment.
- Thin-provisioned disks grew far larger than expected, or snapshot files take up hundreds of gigabytes.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- Thin-provisioned VMs were allocated more combined space than the datastore actually has, and their real usage caught up.
- Forgotten snapshots, or snapshots left behind by failed backups, grew until they filled the datastore.
- Swap files created when VMs power on need free space that no longer exists.
- Logs, ISO images or old VM copies stored on the same datastore gradually consumed capacity.
- The underlying LUN or storage array volume ran out of space even though vSphere showed headroom.
Why it matters
When a datastore fills, every VM writing to it pauses at once, which can take down file servers, databases, email and line-of-business applications simultaneously. Users lose access mid-task and unsaved work may be affected. Freeing space under pressure is risky, because deleting the wrong file, such as a snapshot delta or a VM's disk, can cause permanent data loss. Thin provisioning makes the problem easy to miss until it happens, so monitoring and capacity planning matter for avoiding a repeat.
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
Will the paused VMs lose data?
VMs are suspended at the point they couldn't write, and most resume normally once space is available. Applications that were mid-transaction should be checked afterward, which we do as part of the work.
Can we just delete some files on the datastore?
Deleting files directly on a datastore is risky because many belong to running VMs or snapshot chains. We identify what is safe to remove before freeing anything.
Do we need more storage?
Not always. Reclaiming orphaned snapshots and unused files often frees enough room. If growth is genuine, we explain the options in plain English.