Can't increase HDD Space on a Virtual Machine

[jmontgomery2]

Attempting to increase the Disk Size of a Virtual Machine.  We are getting the following error below.  The Datastore has more than enough available disk space...It is showing 7.63 TB available.  Just trying to attempt to increase the VM by 100 GB....so that size should not be an issue.

"Insufficient disk space on datastore the disk the extend operation failed there is not enough space on the file system for the selected operation:

[maksym007]

Check snapshots maybe some of them are longer than needed

[stadi13]

Is it also available on the storage it self. Have seen this message yesterday as a customer ran out of storage capacity where as the datastore shown nearly 1 TB of free space. This is possible due to overprovisioning on the storage.

[maksym007]

What type of Datastore are you using? VMFS 5 or VMFS 6 or NFS 3 or NFS 4 ? 

[NicoRenard]

Are you using vSAN? if yes, does the reservations features are activated?(operations/host rebuild) 

[jmontgomery2 · Accepted solution]

I am new to this environment....I dug around long enough to figure out that they had created a vSAN and that approximately a month ago someone had shut of the Witness VM. Once I found it and powered it back on....tada I could make the necessary changes...I also put a strongly worded note to not shut off that machine for any reason...LOL

[NicoRenard]

hahaha awesome! Cool you found the problem 👍

[stadi13]

Congratulation 🙂 - Please make sure you mention the usage of your underlying storage system the next time when describing the issue so we can delimit the root cause.

For housekeeping - please mark the reply with the answer as solution so this thread will be markes as solved.

Regards