kern.ipc.maxpipekva console messages starting with 21.02 upgrade
I am seeing the following message every 5 seconds on the console (and in the system general log) since upgrading to 21.02 on an SG-3100.
kern.ipc.maxpipekva exceeded; see tuning(7)
That relevant portion of that man page states:
The kern.ipc.maxpipekva loader tunable is used to set a hard limit on the amount of kernel address space allocated to mapping of pipe buffers. Use of the mapping allows the kernel to eliminate a copy of the data from writer address space into the kernel, directly copying the content of mapped buffer to the reader. Increasing this value to a higher setting, such as `25165824' might improve performance on systems where space for mapping pipe buffers is quickly exhausted. This exhaustion is not fatal; however, and it will only cause pipes to fall back to using double-copy.
- Any thoughts on why 21.02 is unhappy about my environment / setup when 2.4.5 was not?
- What is the best way to configure another value for this kernel parameter?
- How do I determine what that better value should be?
We are tracking some other problems on the 3100 which may be related, but I don't know that anyone else has reported that specific message yet.
What packages do you have enabled on there? And what features? (e.g. IPsec)
- Avahi 2.1_1
- aws-wizard 0.9
- Cron 0.3.7_5
- ipsec-profile-wizard 1.0_2
- openvpn-client-export 1.5_5
I was running pfBlockerNG like many others, but I have completely removed it for the moment.
I am not using IPSec, but i do have an OpenVPN server running.
I have a moderate number of VLANs.
I could maybe see Avahi being related but it's hard to say.
Do you have RAM disks enabled for
/tmp? I know that consumes kernel memory which could maybe contribute to the error you're seeing.
@jimp I only had what was configured OOTB for 21.02. However, I have now downgraded to 2.4.5p1 -- so will have to leave this topic for another day.