---
title: "STACKIT SQL Server Flex"
description: "Managed Microsoft SQL Server instances delivering high availability via SQL AlwaysOn clusters in a certified cloud environment."
scfAsset:
  category: "service"
  managed: true
  marketplaceUrl: "https://marketplace.stackit.cloud/en/products"
  tags: ["MSSQL", "SQL Server", "Database", "AlwaysOn", "Microsoft"]
  maintainers:
    - user: "alexander.gabert"
source_url: "https://framework.stackit.cloud/data-and-ai/assetcontainer/stackit/stackit-service-sql-server-flex/"
source_file: "docs/data-and-ai/assetcontainer/stackit/stackit-service-sql-server-flex.mdx"
---

STACKIT SQL Server Flex delivers managed Microsoft SQL Server instances backed by enterprise AlwaysOn availability clusters.

## Service Overview
- **Mission-Critical Performance**: Enterprise-grade high availability using SQL AlwaysOn 3-node clusters.
- **Reduced DBA Overhead**: Automated maintenance, patching routines, and automated snapshot backups.
- **Compliant Platform**: Operated in BSI C5 certified German data centers with pay-per-use licensing.

## Technical Details
- **Administrative Tooling**: Native support for SQL Server Management Studio (SSMS), SQL Agent Jobs, and custom server roles.
- **Backup Options**: Automated PITR backups alongside manual copy-only backups to S3 object storage.

## Plans

The values below come from the STACKIT documentation and update themselves.

> From the STACKIT docs: [Plans and performance classes of SQLServer Flex › Plans](https://docs.stackit.cloud/products/databases/sqlserver-flex/reference/plans-and-performance-classes-of-sqlserver-flex/#plans) (Source updated 19.11.2025, copied 05.10.2026)

Currently we offer four different plans.

By selecting the plan, you specify the hardware specifications of the SQLServer Flex instance. The available plans depend on the instance type. You can further filter the options by defining the required amount of CPUs and RAM.

If your performance class is too small you are able to upgrade it to a bigger one.

To upgrade it please open a service request at the STACKIT Help Center.

| Service Plan | CPU | RAM | System Disk Size | Plan ID | SQL Server Edition | High Availability |
| --- | --- | --- | --- | --- | --- | --- |
| SQLServer-Flex-4.16-Single-Standard-EU01 ( 4 vCPU 16 GB RAM ) | 4 | 16 GB | 20 GB | 4.16-Single | SQL Server Standard | None |
| SQLServer-Flex-4.32-Replica-Enterprise-EU01 ( 4 vCPU 32 GB RAM ) | 4 | 32 GB | 20 GB | 4.32-Replica | SQL Server Enterprise | 3 Way AlwaysOn Availability Group |
| SQLServer-Flex-8.64-Replica-Enterprise-EU01 ( 8 vCPU 64 GB RAM ) | 8 | 64 GB | 20 GB | 8.64-Replica | SQL Server Enterprise | 3 Way AlwaysOn Availability Group |
| SQLServer-Flex-16.128-Replica-Enterprise-EU01 ( 16 vCPU 128 GB RAM ) | 16 | 128 GB | 20 GB | 16.128-Replica | SQL Server Enterprise | 3 Way AlwaysOn Availability Group |

The selected size is used 75% for storing data and 25% for storing logs.

## Limitations & Constraints
- **No Storage Shrinking**: Storage size reductions are blocked.
- **No Manual Storage Class Changes**: Storage performance tiers are permanently set at initial instance creation.
- **No Automated S3 Immutable Archiving**: Offloading backups to ransomware-protected immutable S3 buckets must be run manually.

<LinkCard title="STACKIT SQL Server Flex Documentation" href="https://docs.stackit.cloud" />