60F frequently crashing

[MeoDub]

I recently replaced our FortiGate 60E devices with brand new 60F units (clean config build). Since going live, the HQ 60F has been highly unstable.   We've experienced multiple unexpected reboots, almost on a daily basis.  The 60E's were rock solid for years, but this new device has been nothing short of a disaster. 

• kernel entering extreme low memory and conserve mode
• sslvpn process timeouts
• watchdog triggered lockups
• spontaneous reboots

I'm a bit shocked at how slow official support has been to respond/assist, so I'm hoping the community can provide better guidance or insight.  

We are running the latest mature release, v7.2.11 build1740 (GA.M).  Has anyone experienced anything similar with 7.2.11 or this hardware? Should I consider downgrading to 7.2.9 or earlier?  

Outside of looking at different vendors, which is not a quick fix, I'm at a loss. 

Thank you in advance, and I will gladly provide more config/logs.

Crashlog examples:

2796: 2025-07-22 04:09:43 msg="Kernel enters extreme low memory mode"
2797: 2025-07-22 04:22:32 SSL VPN enter conserve mode.
2798: 2025-07-22 04:22:32 sslvpn watchdog timeout, pid 245
2799: 2025-07-22 04:22:33 <00245> firmware FortiGate-60F v7.2.11,build1740b1740,250210 (GA.M) (Release)
2800: 2025-07-22 04:22:33 <00245> application sslvpnd

[22394.945844] INFO: rcu_sched self-detected stall on CPU
[22394.946440] 1-...: (1 GPs behind) idle=28e/1/0x4000000000000000 softirq=111690/111691 fqs=5245
...
[22394.946616] watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [system_task:1]
...
[22394.947316] CPU1: stopping other CPUs
...
[22394.952649] Rebooting in 1 seconds..

[Toshi_Esumi]

@BillH_FTNT If TAC already has a bug ID, please share it with the rest of us.

Thanks,

Toshi

[BillH_FTNT]

Hi Toshi_Esumi, 

I believe that is just a FortiCare number. The TAC team is supporting MeoDub to resolve the Converse Mode issue. If the Converse Mode problem is resolved, I think the SSLVPN crash will also be resolved

Regards

Bill

[Toshi_Esumi]

I hope so. Probably it happens because the 60F has RAM < 2GB.

Toshi

[MeoDub]

Hi Bill, 

I sent you a PM with my info.  Thanks!

[BillH_FTNT]

Hi MeoDub

I have reviewed the logs attached to your ticket and I think the SSLVPN crash is related to Converse Mode. Our TAC team is currently assisting you in resolving the issue with Converse Mode

Bill

[BillH_FTNT]

Hi MeoDub and all,

The is a log "[22394.945844] INFO: rcu_sched self-detected stall on CPU
[22394.946440] 1-...: (1 GPs behind) idle=28e/1/0x4000000000000000 softirq=111690/111691 fqs=5245
...
[22394.946616] watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [system_task:1]
...
[22394.947316] CPU1: stopping other CPUs
..." 

I think there was a large amount of traffic reaching the box at that moment.
@MeoDub, could you please share the system logs, event logs, and traffic logs here or through the FortiCare ticket? I will cross-check and try to reproduce the issue in the lab. If needed, I may create an internal ticket for the Engineering team to investigate further. I’ll share any updates once I receive support from the team.

Regards

Bill