OS Template List #
You can immediately deploy virtual machines from the following OS templates.
Our templates are based on server use cases (minimal configuration / no GUI).
Important: Standard Security Specifications (Common to All Templates) #
Our templates maintain the following as standard specifications to ensure initial safety and consistent operations.
1) OS Internal Firewall (Initial Configuration) #
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By default, the OS internal firewall functionality (e.g., ufw / firewalld, etc.) is disabled.
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Initial access control is primarily handled by network-side firewall (controlled by us).
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Of course, you can also enable and operate the OS firewall on your side as needed.
Note: When enabling the OS internal firewall, be careful not to block your own management access such as SSH.
2) Network-Side Firewall (Standard Policy) #
We apply standard policies on the network side to prevent unauthorized use (Abuse) and ensure stable infrastructure operations.
Inbound (IN / Inbound) #
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Default: Deny (DROP)
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Initial Permissions (Standard):
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SSH: TCP/22 (Inbound Allowed)
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ICMP: Inbound Allowed (for connectivity verification and routing control)
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In the initial state, inbound traffic other than SSH and ICMP is blocked.
If you need web publishing (80/443), etc., please add it via the Network Firewall in the control panel.
Outbound (OUT / Outbound) #
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Standard: Allowlist (Whitelist) Method
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Outbound Permissions by Default (Standard):
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DNS: UDP/53, TCP/53
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NTP: UDP/123
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HTTP: TCP/80
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HTTPS: TCP/443
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QUIC / HTTP3: UDP/443
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ICMP: Outbound Allowed (for connectivity verification and routing control)
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Outbound communications other than the above are generally blocked.
If you need additional outbound ports, please submit a request via support ticket (review and conditional approval may be applied depending on purpose, destination, duration, etc.).
Note: For reasons such as anomaly detection, upstream requests, and attack mitigation, we may restrict ICMP types (Type/Code) or communication conditions.
3) SSH Authentication (Key Authentication Only) #
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SSH password authentication is disabled.
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SSH public key (key authentication) only is accepted.
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Please register your SSH public key at the time of application (or deployment).
If not registered, you will not be able to log in for the first time.
Template Common Specifications #
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64-bit (x86_64 / amd64)
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Cloud-init compatible by default (automatic configuration of initial user / SSH key / network, etc.)
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qemu-guest-agent compatible (stabilization of IP display, shutdown, etc.)
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After the first startup, please perform OS updates and middleware installation yourself
About ISO Bring-Your-Own Installation #
You can install OSs not listed here by bringing your own ISO.
However, with ISO installation, some automatic configurations such as cloud-init may not work.
Recommended Templates (For Production / Long-Term Operations) #
If you’re unsure, we recommend choosing from the following first.
| OS | Recommended Version | Features | Recommended For |
|---|---|---|---|
| Ubuntu Server | 24.04 LTS | LTS (Long-Term Support) / High versatility | Web/AP, Docker, general-purpose use |
| Ubuntu Server | 22.04 LTS | Compatibility-focused (for existing assets) | Migration from existing environments, fixed-requirement configurations |
| Debian | 13 (stable) | Stable, lightweight, server standard | Web/AP, DB, long-term stable operations |
| Debian | 12 (oldstable) | Previous stable version (compatibility tier) | Debian 12-based configurations, migration/validation |
| AlmaLinux | 10.X, 9.x | RHEL-compatible (enterprise standard) | Enterprise systems, commercial middleware |
| Rocky Linux | 10.X, 9.x | RHEL-compatible (strong in operations standardization) | Enterprise use, robust operations, standardization |
CentOS Stream / Fedora (Testing to Production: If Use Case Matches) #
Strong for latest versions and testing purposes, but please confirm your operations policy beforehand.
| OS | Recommended Version | Features | Cautions |
|---|---|---|---|
| CentOS Stream | 10 | Intermediate following “slightly ahead” of RHEL (rolling-biased) | Due to specification changes, Alma/Rocky is recommended for production |
| Fedora Linux | 43 | Fast adoption of latest technologies | Support period is relatively short. For testing and development |
Lightweight Templates (Minimal) #
For use cases where you want to run with minimal configuration and high speed.
| OS | Recommended Version | Features | Recommended For |
|---|---|---|---|
| Alpine Linux | 3.23.x | Ultra-lightweight, fast, simple | Small APIs, proxies, use-case-specific VMs |
| Alpine Linux | 3.22.x | Previous stable series | Compatibility-focused, migration from existing Alpine environments |
Template Update Policy #
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OS templates are updated periodically on a best-effort basis in line with upstream updates.
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We do not provide EOL (end-of-life) OS as a general rule.
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If you need an older version (for migration, validation, etc.), please contact us via support ticket.
Which One Should I Choose? (If Unsure) #
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If unsure: Ubuntu 24.04 LTS
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Stable and lightweight: Debian 13
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Enterprise operations, RHEL-compatible: AlmaLinux 9 / Rocky Linux 9
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Slightly ahead of RHEL, testing purposes: CentOS Stream 10
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Want to try the latest features: Fedora Linux 43
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Ultra-lightweight: Alpine Linux 3.23.x