Hyperv-V creates mystery .avhdx files and fills up disk space

Question

I have windows server 2016. Also i have Hyper-V role on my server. Every day in 5:36 i have error, that disk full and my virtual machine is stopping. In Hyper-V logs:

   ProviderName: Microsoft-Windows-Hyper-V-StorageVSP

TimeCreated                     Id LevelDisplayName Message
-----------                     -- ---------------- -------
11.03.2018 5:36:08               5 Information         Storage device 'D:\DBS82-Data.vhdx' changed recovery state. Previous state = Recoverable Error Detected, New state = Recoverable Error Detected.
11.03.2018 5:36:08               4 Information         Storage device 'D:\DBS82-Data.vhdx' received a recovery status notification. Current device state = Recoverable Error Detected, Last status = No Errors, New status = Disk Full.
11.03.2018 5:36:08               6 Information         Storage device 'D:\DBS82-Data.vhdx' received an IO failure with error = SRB_STATUS_ERROR_RECOVERY. Current device state = No Errors, New state = Recoverable Error Detected, Current status = No Errors.

I tried to no sleep until 5:36 to see, what is going on, because on my disk D i have 80 G of free space. DBS82-Data.vhdx is near 100 G. So, i tried to no sleep and i saw, that on disk D was created DBS82-Data_E8D5659C--CBA3-4813-8543-F30F264A7A2F.avhdx file that fills up disk space. Also, in a Hyper-V manager i see in status of all virtual machines status merging. What is that ? Where i can manage it process ? Because on hyper-v in windows server 2008, i did not saw this problem (feature).

@joeqwerty no, maybe other admin was set something, but he will absent and i should find out answer, where i can see these options — Piduna, Mar 11 '18 at 15:29

score 13 · Answer 1 · answered Mar 18 '18 at 11:20

13

You have either enabled the Hyper-V Checkpoints that need to be merged or there is an additional snapshot managing software (backup or replication) that sends the command to Hyper-V for creating checkpoints/snapshots.

I would start with investigating the systems/application logs at the mentioned time to find out the root cause of the issue.

answered Mar 18 '18 at 11:20

Net Runner

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A fun fact for future readings -- turning off Checkpoints and deleting the "Automatic Checkpoint" causes a merge operation to happen. I did that after shutting off the Windows 10 VM and things went smoothly enough. Regained about 20-30 GB of my 256 GB SSD that way! :) – starlocke Mar 24 '20 at 15:22

Hyperv-V creates mystery .avhdx files and fills up disk space

1 Answers1