Got a specific OS or distro in mind that's not in our default list? No sweat! Nebula Core lets you install any custom ISO by streaming it from a remote URL – perfect for unique setups like specialized Linux flavors, recovery tools, or even custom Windows builds. It's streamed (not uploaded to our servers), so it's fast and secure.
This guide is for beginners – we'll cover adding the ISO, mounting it, and booting into install mode. Takes about 5-10 minutes, plus install time. (Pro tip: Back up your VPS first via Nebula Core – check my post-order guide (link-to-post-order-article) for basics!)
Why Use a Custom ISO?
- Flexibility: Install anything – from Rocky Linux tweaks to Veeam recovery media.
- No limits: Not stuck with our templates; bring your own.
- Quick recovery: Great for troubleshooting or OS swaps without full redeploy.
Streamed magic: Nebula Core pulls the ISO live – no huge uploads.
Warning: This overwrites your current OS – data gone! Backup snapshots or files first. Ensure your ISO URL is public and direct (e.g., ends in .iso).
Step 1: Log In to Nebula Core
- Head to your MyRack client area (my.lunarracks.com) > Services > Click your VPS > OPEN CONTROL PANEL.
- Or direct: Use the link from your welcome email.
Tip: Bookmark Nebula Core for quick access – it's your VPS command center.
Step 2: Add Your Custom ISO
- In Nebula Core
- Click Self Install under the Operating System section (in the Server Setup...).
- Click Rebuild first if the VPS already has an OS installed.
- Click Self Install. The server will then provision.
- Once provisioned, click Media.
- Under click Custom CD/DVD.
- Enter the direct URL to your ISO file (e.g., https://example.com/my-custom-os.iso).Make sure it's a valid, public link – test in browser first (should download).
- No auth or redirects – direct HTTP/HTTPS only.
- Click Insert.
Pro Tip: Host your ISO on a reliable site like your own server or public mirrors (e.g., CentOS/Alma archives). Avoid slow links to prevent timeouts.
Step 3: Mount the ISO & Reboot
- Back in Nebula Core > Reboot your VPS (Overview tab > Reboot).
- Open Console (noVNC) – Options -> Browser VNC
- It should boot into the ISO's installer.
Step 4: Run the Installation
- In the console, follow the ISO's setup wizard (e.g., for Linux: Partition disks, set root password).
- For Windows/custom: Enter product keys if needed.
- Once installed, Eject ISO CD/DVD (Media tab > Eject) > Reboot again.
- VPS boots into your new OS – access via SSH/RDP with fresh creds.
Note: Initial boot may take longer – watch console for errors.
Troubleshooting: Common Hiccups
| Issue | Fix |
| "Invalid URL" error | Check link - must be direct .iso (no zips). Test download in incognito. |
| ISO not showing | Refresh page or log out/in. If stuck, contact our support. |
| Boot fails / Black screen | Wrong ISO arch (x86 vs ARM?) Eject, Reinsert, reboot. Try UEFI/BIOS toggle in Options > Settings |
| Timeout during stream | Slow source? Use a faster host or mirror. Retry add. |
| Post-install no network | Configure the IP in the OS (ifup/ifconfig). Nebula auto-assigns - check Credentials tab. |
Bonus: Best Practices
- Test first: Use a non-prod VPS or snapshot rollback.
Quick Recap (Cheat Sheet)
| Step | Action |
| 1 | Log into Nebula via MyRack |
| 2 | Media menu > CD/DVD ROM > Enter ISO link > Insert |
| 3 | Reboot VPS |
| 4 | Console > Install OS > Eject > Reboot |
Need Help?
Glitch?
- Screenshot the error and submit a ticket: https://my.lunarracks.com/submitticket.php
- More deets: Check our Knowledgebase portal.
Custom OS unlocked!
Now tweak to your heart's content. Build epic – we're here if you need us.
