Upgrade Failure

Nokia 7705 SAR: How to rollback to the previous image after a failed upgrade

Q: Where can I find the Nokia official documentation?

https://documentation.nokia.com — search the product family + feature name.

By Sai Kiran Pandrala · reviewed by Sai Kiran Pandrala, Editor Last verified: 2026-05-30

⚡ At a glance

Vendor	Nokia
Operating system	SR OS / SR Linux
Category	Upgrade Failure
Skill level	Intermediate to advanced
DIY-able?	Yes with CLI access; some scenarios need Nokia Customer Care + RMA.

An upgrade on Nokia 7705 SAR is really three jobs: stage the image, verify integrity, activate. Skipping verify is how you end up with a half-bricked unit at 2am: I have done it exactly once and learned for life.

SR OS / SR Linux provides clear pre- and post-checks. `show version` before and after is the bare minimum; ideally also `admin tech-support` so Nokia Customer Care has a clean before/after diff.

The procedure below assumes you can take a maintenance window. If you cannot, ISSU / hitless options exist on some platforms but vary by code train, check SR OS / SR Linux release notes first.

What this guide covers

Rollback to the previous image after a failed upgrade on a Nokia 7705 SAR (SR OS / SR Linux).

Step-by-step

Confirm there's a previous image still on flash.
Set the boot variable to that previous image.
Reboot.
Verify the version is back to the prior release.
Investigate the upgrade failure separately. do not re-attempt without root cause.

CLI / commands

# Boot recovery prompt: BOF> (Boot Options File)

# Verify image
show version

# Upgrade
file copy cf3:/timos-21.10.R1.tim cf3:/timos.tim

# Save / commit
admin save

# Rollback
rollback

Recovery options

Boot loader recovery (BOF> (Boot Options File))
Rollback to the previous image with rollback
Force failover to a known-good standby (HA platforms)

Frequently asked questions

Will this work on my specific SR OS / SR Linux version?

The procedure reflects current SR OS / SR Linux behaviour. Older releases may need minor syntax adjustments, use the CLI help (? or tab-completion) to verify.

Should I open a Nokia Customer Care case immediately?

Open one if you suspect hardware failure or the symptom persists after a maintenance-window reload. Make sure your support entitlement is active first.

Where can I find the Nokia official documentation?

https://documentation.nokia.com: search the product family + feature name.

Is this procedure safe in production?

Test in a lab or maintenance window first. Capture pre-change state so you can roll back.

All Nokia fix guides → /nokia/
All vendor guides → /vendors/

Related guides worth a look while you sort this one out:

References

Nokia support portal: https://customer.nokia.com
Nokia knowledge base: https://documentation.nokia.com
Nokia security advisories: https://www.nokia.com/about-us/security/vulnerability-management/
Open a case: https://customer.nokia.com

Reference material, not professional advice. Validate against your specific SR OS / SR Linux version and test in a non-production environment before applying.

What changed recently?

Fault diagnosis on a Nokia device goes faster when you map the symptom to a recent change:

Did firmware update in the last 7 days?
Did the network (router, ISP, VPN) change?
Was the device moved physically?
Did paired devices (phone, hub, app) update?
Were any accessories swapped in or out?

The answer narrows the root cause to a manageable subset.

Before you start

A few things to confirm so the Nokia device fix goes cleanly:

Latest firmware downloaded if you're going to update.
Warranty + support contract status checked, opening sealed parts may void it.
Backup of current configuration (where applicable) taken.
Spare parts on hand if you anticipate replacement.
Adequate workspace, lighting, and time. rushing causes regressions.

Quick verification

Before you walk away from a Nokia device fix, run through:

1. Reproduce the original trigger, does the issue reappear? 2. Check the device's status / health screen for any new alerts. 3. Confirm paired devices (app, hub, controller) reconnected. 4. Save / commit any configuration changes per the device's normal workflow. 5. Note the change in your maintenance log with date + firmware version.

Escalation guide

For a Nokia device, the right escalation depends on impact:

Cosmetic / minor: log a ticket via the Nokia app or web portal. Response 1-3 business days.
Mid-impact: phone support. Have your serial number ready.
Critical (production down, safety issue): in-person dealer / TAC visit. Bring proof of purchase.
Out of warranty: third-party repair shop with manufacturer-certified technicians.