Rapid Deploy Disk space usage

Understanding Your Rapid Deploy Server

If you have recently looked at the disk usage on your Rapid Deploy server and thought, “Wait, I didn’t use that much space,” you are not alone. It is a common question we get here at InterServer.

To understand where that space is going, we first need to look at how these servers are built. Rapid Deploy systems are single-server systems that are virtualized. In plain English, they are designed to be fast, stable, and feature-rich. Because we use KVM (Kernel-based Virtual Machine) technology and the ZFS file system, you get some powerful perks right out of the box:

• Easy Reinstalls: Wipe and reload your OS quickly.
• Snapshots: Automatic point in time restore points of your file system state.
• RAID with Monitoring: Our techs keep an eye on drive health for you.
• ZFS File System: A robust system that prevents data corruption.

These features are great for keeping your data safe and your management easy, but they do change how your disk space is reported. Here is the breakdown.

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1. Local Reinstall Templates

One of the best features of Rapid Deploy is the ability to reinstall your operating system in minutes rather than hours. To make this happen, we keep OS templates stored locally on your system.

Think of these like keeping a spare tire in your trunk. You might not need it today, but it takes up space so it’s there when you do. These templates typically occupy 50 to 75 GB of disk space.

Can I remove them?
Yes. If you need that space back and do not plan on reinstalling your OS anytime soon, you can request that we remove these templates. Just remember: if you decide to reinstall in the future, you will need to ask us to re-enable them first.

2. ZFS Snapshots

We use the ZFS file system because it allows for “snapshots.” A snapshot is like a photo of your server at a specific moment in time. If you accidentally delete a critical file or an update breaks your site, these snapshots can be a lifesaver.

We generally keep snapshots for 24, 48, and 72 hours. However, there are rules to keep your server running smoothly:

• Snapshots take up space because they hold onto the data of files you have changed or deleted.
• If your real disk usage goes over 80%, the system stops creating new snapshots to prevent the drive from filling up completely.

3. The “Trim” Factor (Fstrim)

This one is a little more technical, but it accounts for a lot of confusion. When you delete a file inside your Virtual Machine (VM), the underlying storage system doesn’t always know that space is free immediately. It waits for a command called fstrim (or just “trim”).

Here is the situation:

• OS Support: Most modern Operating Systems support trim, but some do not. If your OS doesn’t fully support it, that space will continue to be reported as “used” even though you deleted the files.
• Timing: Even if your OS supports it, fstrim might not run constantly. It usually runs on a schedule.

This means you might have plenty of space available, but the system hasn’t reported it as “free” yet. That space is technically available if you need to write new data to it, but your monitoring tools might tell you the disk is fuller than it actually is.

4. The Silver Lining: ZFS Compression

While the features above consume disk space, the ZFS file system also has a built-in way to save it. By default, we use lz4 compression on your data.

This is a “light” compression, meaning it is extremely fast and doesn’t slow down your server’s performance. It works silently in the background, compressing files as they are written to the disk.

What does this mean for you?

• Text is Tiny: Highly compressible files—like logs, database text, and configuration files—take up significantly less space on the physical disk than they do on your computer screen.
• Efficient Storage: This helps offset some of the space used by snapshots and templates. You are essentially getting a storage boost for text-heavy data without having to configure anything yourself.

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Do You Want to See All Your Space?

We enable these features by default because they provide a safety net and convenience for most users. However, we understand that sometimes raw storage space is the priority.

If you prefer to have every gigabyte available for your own files, snapshots and local templates can be disabled. This will free up the reported usage, giving you a cleaner look at your disk space—just keep in mind you will lose the quick-restore safety net those features provide.

If you have questions about your specific usage or want to tweak these settings, just open a ticket with us.