Skip to content

PFSense 2.4.5 on Hyper-V following 2020-05 Cumulative Update

Following applying the 2020-05 Cumulative Update for Windows Server 2016 (1607), a PFSense 2.4.5 Hyper-V virtual machine on this host OS suddenly became very unstable.

The machine appears to experience high load averages immediately following boot, with a large percentage of the vCPU usage (>99%) being shown as “system” in top.

Additionally, sometimes it is seen that the pfctl process is also using close to 100% of a CPU. The system is unresponsive, or intermittently responsive throughout this time — both in terms of the console, the web UI, and packet forwarding that the machine should be doing.

After a few minutes, Hyper-V appears to restart the guest OS. This isn’t a PFSense kernel panic and no dump is made by PFSense.

I spun up a new VM of the unstable daily snapshot of PFSense, a Generation 2 UEFI-based VM. This completely eliminated these problems for us in this new VM — it works fine, routes just fine for what we’re doing and is responsive.

I don’t have a solution — I just want to throw this issue out there in case others have experienced it, in case we might work together to figure out what’s going on here.

Like this post?

If you would like to support the time and effort I have put into my tutorials and writing, please consider making a donation.

Post a Comment

On some sites, you must be logged in to post a comment. This is not the case on this site.
Your email address is not made public or shared. Required fields are marked with *.

Posting a comment signifies you accept the privacy policy.
Please note — your comment will not appear straight away, as all comments are held for approval.