# Extreme Universal switch OS-name mapper

> ExtremeXOS is Switch Engine and VOSS is Fabric Engine — but only on Universal hardware, and the image files and boot menus still use the old names. Give a model series or an OS name and see which applies, the version the rename landed at, and the caveats that come with the series. It states plainly that changing persona deletes the configuration. Local and offline.

- Tool: https://ronutz.com/en/tools/extreme-switch-os-mapper
- Family: Operations & Fieldcraft

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## What it does

Give a model series or an OS name and the tool says which naming applies, which versions the rename landed at, and what comes with that particular series. The two naming pairs are shown **before any input**, because somebody arriving after a document said one word and their switch said another needs the answer immediately.

## The rename, in one line each

- **ExtremeXOS (EXOS) → Switch Engine**, from 31.6
- **VOSS → Fabric Engine**, from 8.6

Both apply **only to Universal hardware**: 4120, 4220, 5320, 5420, 5520, 5720, 7520, 7720. Anything else keeps the original names, and **the image filenames and boot menus still use them too** — so a boot menu offering to change the OS "to VOSS" on a Fabric Engine switch is neither a bug nor a stale build.

## The warning it always gives

**Changing persona deletes the configuration.** Extreme's own wording: changing the network operating system deletes all configuration files, debug information, logs, events and statistics belonging to the previous one. **It is a rebuild, not a migration**, and the tool says so on every lookup rather than only when a model is recognised.

It also flags the boot question being asked in the negative — **N keeps Switch Engine, Y moves to Fabric Engine**.

## Series caveats it surfaces

- **7520**: stacking works under Switch Engine and **not** under Fabric Engine. If the design needs stacking, the persona choice is already made.
- **5420 and 5520**: upgrading to Switch Engine 31.6 **changes the SNMP SysObjectID**, so monitoring that identifies the device by that value stops recognising it — with nothing looking wrong from the console.
- **Fabric Engine minimums differ**: 8.6 on the 5320, 5420 and 5520; 8.7 on the 5720.

## What it will not do

It works at series level rather than by individual part number, deliberately: the naming question is answered by series, and a table of SKUs would go stale faster than it helped. It does not know your inventory or your installed versions.

## Standards and references

- [Extreme Networks - ExtremeXOS and Switch Engine 31.6 release notes, recording the rename](https://documentation.extremenetworks.com/release_notes/ExtremeXOS_SwitchEngine/31.6/GUID-063FF7DF-34E8-494C-AFAB-848B1A0068B3.shtml)
- [Extreme Portal - What is Switch Engine (EXOS) and Fabric Engine (VOSS)?](https://extreme-networks.my.site.com/ExtrArticleDetail?an=000102405)
- [Extreme Networks - Switch Engine release notes: persona change deletes configuration, and the boot-menu sequence](https://documentation.extremenetworks.com/release_notes/SwitchEngine/33.1.100/GUID-EEE4A4A1-99DC-4691-B6B5-F88A6FA8042F.shtml)

## Related reading

- [Switch Engine, Fabric Engine, and the switches that kept the old names](https://ronutz.com/en/learn/extreme-universal-os-names.md): Extreme renamed two operating systems on some hardware and not others, while the image files and boot menus kept the originals. Plus the part that matters more than the naming: changing persona deletes the configuration.