> ## Documentation Index
> Fetch the complete documentation index at: https://docs.gcore.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Install an OS from an ISO image

> Install an operating system from a custom ISO image in VMmanager by mounting a public URL as a bootable disk and rebooting the server.

Use a custom ISO image to install operating systems that are not available as built-in VMmanager templates. Provide a public HTTP or HTTPS URL to an ISO image (up to 8 GB). VMmanager downloads the image, mounts it as a bootable disk, and restarts the server from it. Only one ISO image can be mounted on a server at a time.

> [!WARNING]
>
> Installing from ISO erases all data on the server disk. Back up any important files before proceeding.

**1. Open VMmanager 6**

In the [Gcore Hosting Portal](https://hosting.gcore.com/billmgr), navigate to **Products/Services** → **Virtual private servers**, select the server checkbox, and click **To panel**.

![Virtual private servers list with a server row selected and the To panel button highlighted in the toolbar](https://mintcdn.com/gcore/494jjlOXZiI1ohtY/images/docs/hosting/virtual-servers/manage/operating-system/install-a-linux-os-from-your-iso-image/install-a-linux-os-from-your-iso-image-image1.png?fit=max\&auto=format\&n=494jjlOXZiI1ohtY\&q=85\&s=1c1200d13c4777beaaae5bffa145a4db)

**2. Open the ISO mount dialog**

In VMmanager 6, go to the **Virtual machines** list. Open the three-dot menu on the right side of the server row and select **Mount ISO-image**.

![VMmanager 6 virtual machines list with the three-dot menu open and Mount ISO-image option highlighted](https://mintcdn.com/gcore/bP_M3iNvkCNJWoX1/images/docs/hosting/virtual-servers/manage/operating-system/install-a-linux-os-from-your-iso-image/install-a-linux-os-from-your-iso-image-image2.png?fit=max\&auto=format\&n=bP_M3iNvkCNJWoX1\&q=85\&s=5573c1a5cbe1e71aabe98da0ef0c4395)

**3. Enter the ISO image URL**

In the **URL** field, enter a direct link to the ISO file.

![Upload ISO-image page with URL field and Tags field](https://mintcdn.com/gcore/bP_M3iNvkCNJWoX1/images/docs/hosting/virtual-servers/manage/operating-system/install-a-linux-os-from-your-iso-image/install-a-linux-os-from-your-iso-image-image3.png?fit=max\&auto=format\&n=bP_M3iNvkCNJWoX1\&q=85\&s=e6298025b49b31f7adaec6d95072c9af)

> [!NOTE]
>
> Add **Tags** to trigger VMmanager automation scripts that use matching tag values.

**4. Download and connect**

Click **Download and connect**. VMmanager downloads the ISO image, mounts it as a bootable disk, and reboots the server from it automatically.

**5. Complete the installation via VNC**

After the server reboots, connect via [VNC](/hosting/virtual-servers/manage/connect/connect-to-a-virtual-server-via-vnc) to reach the installer. The ISO boot menu appears in the console. Follow the installer steps to complete the OS installation.

> [!NOTE]
>
> After the installation is complete, disconnect the ISO image to restore normal boot: open **Virtual disk** in the left sidebar, disconnect the mounted ISO image, and restart the server.