How Many Firmware Images Are Supported on Dell Switches?

In enterprise network environments, firmware management is not just a maintenance task—it is a key part of risk control. One of the most common questions administrators ask is: how many firmware images are supported on Dell switches?

The short answer is simple, but the implications matter. Understanding how Dell handles firmware images directly affects upgrade planning, rollback capability, and overall network stability.

This guide explains how Dell switch firmware image storage works, how to manage it via CLI, and how to reduce risk during upgrades—especially in production networks.

• Part 1: Firmware Image Architecture Overview
• Part 2: Managing Firmware Images via CLI
• Part 3: Upgrade Strategy and Risk Management
• Part 4: FAQ – Dell Switch Firmware Images

Part 1: Firmware Image Architecture Overview

Most modern Dell Networking switches—including N-Series, S-Series, and switches running SmartFabric OS10—use a dual-image (dual-partition) architecture.

In practical terms:

Dell switches support two firmware images only.

These images are stored in two dedicated flash partitions:

• Active Partition – The firmware image currently running on the switch and used for the next reboot.
• Standby (Backup) Partition – A secondary image slot used to stage a new firmware version or retain the previous version for rollback.

This design provides built-in protection during upgrades. If a newly installed image fails to boot or introduces unexpected behavior, the switch can revert to the previous firmware stored in the alternate partition.

Part 2: Managing Firmware Images via CLI

While Dell switches vary slightly by operating system (OS9 vs OS10), the firmware image workflow is consistent across platforms.

Checking the Current Firmware and Partition Status

Example CLI command to verify the running software version:

show version

To view which image is active and what is stored in the standby partition:

show boot detail

This command is essential before and after any upgrade, especially in production environments.

Downloading a Firmware Image

Firmware images are typically transferred using SCP, FTP, or TFTP.

Important note: downloading an image does not install or activate it. The image must be explicitly installed to a partition.

Installing to the Standby Partition

During a standard upgrade, the new firmware image is installed to the standby partition, while the active image continues running.

This preserves a known-good rollback option throughout the upgrade process.

Switching the Boot Partition

After installation, configure the switch to boot from the standby partition on the next reload:

boot system standby
reload

If the upgrade is successful, the standby image becomes the new active image.

Synchronizing Firmware Images on OS10

On Dell OS10 switches, administrators may choose to synchronize both partitions after validating a successful upgrade:

image copy active-to-standby

This step is optional but commonly used to standardize firmware across both partitions.

Part 3: Upgrade Strategy and Risk Management

Rollback Protection

The dual-image architecture is the primary safety net during firmware upgrades.

Starting with OS10 release 10.5.1.0, Dell introduced a unified partition model. Even if the standby image appears as “N/A” in CLI output, the system internally retains the previous version for rollback purposes.

VLT (Virtual Link Trunking) Upgrade Order

In high-availability environments using VLT, upgrade order is critical:

1. Upgrade the secondary VLT node first.
2. Allow it to reboot and stabilize on the new firmware.
3. Proceed with the primary VLT node.

This approach maintains traffic forwarding and minimizes service disruption.

OS9 to OS10 Migration Considerations

Migrating from OS9 to OS10 is not a simple partition switch.

• The process requires a clean installation via ONIE.
• Existing disk partitions and configurations are removed.
• Configuration backups are mandatory before migration.

This is a common source of failed upgrades when not planned properly.

Part 4: FAQ – Dell Switch Firmware Images

Q1.Can I store more than two firmware images on a Dell switch?

No. Dell switches are designed to support only two firmware images, stored in dual partitions. Additional images cannot be stored locally on the device.

Q2.Does upgrading firmware delete my configuration?

A standard CLI-based upgrade preserves the startup configuration. However, ONIE-based installations—such as OS9 to OS10 migrations—erase all configurations.

Q3.How can I quickly revert to the previous firmware version?

You can switch the boot partition back to the standby image and reload the switch. On OS10 versions 10.5.2.0 and later, Dell also provides a rollback script to automate this process.

Q4.Why does show boot detail display “N/A” for the standby image?

On some OS10 releases using a unified partition model, the standby image may appear as “N/A” even though the previous version is still retained internally for rollback.

Final takeaway: Dell switches support two firmware images only, and understanding how those partitions work is essential for safe upgrades in production networks.