Deboarding Lucidity Managed Disk
What is Deboarding?
Deboarding is essentially the reverse of an onboard operation. Deboarding removes specific disks from the management of Lucidity AutoScaler, returning them to their original configuration. This allows you to stop storage autoscaling on specific volumes while keeping your data intact. You can deboard an onboarded disk directly from the Lucidity Dashboard.
Reboot requirements
Deboarding requires a reboot in every case except Windows data volumes
Note: Deboarding is supported for both data and root partitions on Linux and Windows.
To deboard a disk:
Once logged into the Lucidity Dashboard, from the left navigation menu, select Scaler.
Select the Virtual Machine under Managed VMs to bring up the Instance Details page. Click the Mount Point to display the list of onboarded volumes.
Click the three dots under the Actions column next to the volume you wish to deboard and select Deboard Disk.
Specify the volume size you want provisioned for the deboarded volume. The dashboard enforces a minimum size, which is never smaller than the disk you originally had before onboarding. See Minimum Deboarding Size for how this figure is worked out.
Choose to delete the residual volumes after a set number of days and click Deboard. After this period, these disks are fully removed from:
OS view
Cloud provider console
Note: The time taken for the deboard completion depends on the size of the data present on the disk. Once deboarding is complete, the disk appears under Unmanaged VMs again.
Repeat this process for more volumes if needed.
Minimum Deboarding Size
When you deboard a volume, the dashboard shows the smallest size you are allowed to deboard to. This minimum exists to guarantee two things at once: that all your data fits on the new disk with room to spare, and that you never end up with a disk smaller than the one you started with.
The rule
The minimum deboarding size is the larger of:
(A) Your original size — the size of the disk before Lucidity onboarded it. The minimum is never allowed to fall below this.
(B) A data-based minimum — your current used data multiplied by 4/3 (that is, your data plus roughly one third again as free space), rounded up to the next size your cloud provider offers for the disk type.
If Lucidity cannot read how much data is currently on the volume, the volume's current provisioned size is used in place of (B).
This rule applies to both data and root deboarding.
The three inputs
Input | What it means |
|---|---|
Original size | The size of the disk before Lucidity onboarded it — what you are restoring back to. The minimum never drops below this. |
Used space | How much data is actually stored on the volume right now. |
Current size | The volume's current provisioned capacity. Used only as a fallback when used space cannot be read. |
All three values, and the resulting minimum, are shown in GB, matching the units on the dashboard.
Why the dropdown sometimes starts higher than expected
Some cloud providers sell disks in fixed sizes rather than any arbitrary number of GB. Once the calculation above produces a figure, the dashboard rounds it up to the next size your provider actually offers.
This is why the smallest option in the dropdown can be larger than your original disk. For example, if your original disk was 512 GB but your data has grown since onboarding, the calculated minimum may land between 512 GB and 1 TB — in which case the first size you can select is 1 TB, because that is the next size available.
Worked examples
Your situation | Minimum offered | Why |
|---|---|---|
Original 100 GB | The data-based figure, rounded up | Your data has grown past the original disk, so the data-based minimum is the higher of the two. |
Original 500 GB | 500 GB | Your data would fit on something smaller, but the minimum can never go below your original size. |
Original 100 GB | 250 GB | Used space could not be read, so the current provisioned size is used instead. |
Good to know
You can always choose a size larger than the minimum. The figure shown is only the smallest safe target.
Because the calculation uses your current usage, the minimum can change over time as the amount of data on the volume changes.
FAQ
1. Why do I still see extra disks attached to the Virtual Machine after deboarding?
The extra disks seen after deboarding are a copy of your data, retained so you can perform data integrity checks. By default, duplicate disks are kept for 3 days, and this period can be configured while deboarding the disk. Once these disks are deleted, they no longer appear in the operating system view or the cloud service provider portal.
Views from the operating system and cloud provider portal once deboarding is complete:
Cloud Provider View (Azure)
OS Disk — the root/OS partition of the Virtual Machine.
Data Disks:
Lun 1: One single large data disk of the Virtual Machine (back to the original state).
Lun 0, 3: These volumes are a copy of the disks managed by Lucidity, retained by default for 7 days so you can perform data integrity checks.
Windows Operating System
C: — OS/root partition of the Virtual Machine.
D: — Default temporary disk.
F: — Single large disk attached to the VM (back to the original state).
Z: — Copy of Lucidity-managed disks. By default, this volume is retained for 7 days after deboarding.