Stuck with Zero out Disks in OnApp? We can help you.

As part of our Server Virtualization Technologies and Services, we assist our customers with several OnApp queries.

Today, let us see how we can fix this issue.

Zero out Disks in OnApp

When we delete or migrate a VS’s disk, OnApp Cloud provides two ways to clean the VS data.

By default, it will format the physical disk space used by a virtual server when we delete or migrate to another data store.

We can also choose to zero out a VS’s disk (filling it with zeroes), which will then take effect for operations queued both via the UI and the API.

We need to make note that this method is likely to have a noticeable impact on deletion time and the load placed on the Data Store whilst disks are being filled with zeros since it is a more intensive IO operation.

In addition, it is important to consider that if we enable thin provisioning at the SAN side for LVM DataStores, we need to enable this option for space reclamation to happen successfully.

We can discuss this with the SAN vendor for their recommendation.

Moving ahead, let us see how we can enable this behavior.

To do so, our Support Techs suggest the following steps:

• Initially, we log in via SSH to the Control Panel server
• Then, to edit, we open the following configuration file:

/onapp/interface/config/on_app.yml

• We set the wipe_out_disk_on_destroy parameter from false to true:

wipe_out_disk_on_destroy: true

• Later, we restart the OnApp service:

service onapp restart

• Now when deleting disks we will see something along the lines of the following in the logs:

Running: dd if=/dev/zero of=/dev/onapp-cmd7y65etpxii8/hkct05vbu21fma bs=4M count=256 conv=notrunc oflag=direct

[Couldn’t figure it out? We’d be happy to assist]

Conclusion

In short, we saw how our Support Techs go about the Zero out Disks in OnApp query.