How to ensure Virtual Server disks are being securely erased when a Virtual Server or one of its disks is destroyed?
OnApp Cloud provides two ways to clean the VS data when deleting or migrating a VS's disk. By default, OnApp Cloud will format the physical disk space used by a virtual server when that VS's virtual disk is deleted, or when the VS's disk is migrated to another data store.
You can also choose to zero out a VS's disk (filling it with zeroes) with the change described below, which will then take effect for operations queued both via the UI and the API.
Note that this method is likely 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.
Important: if you enable thin provisioning at the SAN side for LVM DataStores, you may need to enable this option for space reclamation to happen successfully. Please discuss with your SAN vendor for their recommendation.
To enable this behaviour:
- Log in via SSH to your Control Panel server
- Open the following configuration file for editing:
- Set the wipe_out_disk_on_destroy parameter from false to true:
- Restart the OnApp service:
service onapp restart
- Now when deleting disks you would 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