Hi,
in the last week, after updating to 6.6.92, we’ve encountered a number of VMs reporting temporarily hung tasks blocking the whole system for a few minutes. They unblock by themselves and have similar tracebacks.
The IO PSIs show 100% pressure for that time, but the underlying devices are still processing read and write IO (well within their capacity). I’ve eliminated the underlying storage (Ceph) as the source of problems as I couldn’t find any latency outliers or significant queuing during that time.
I’ve seen somewhat similar reports on 6.6.88 and 6.6.77, but those might have been different outliers.
I’m attaching 3 logs - my intuition and the data so far leads me to consider this might be a kernel bug. I haven’t found a way to reproduce this, yet.
Regards, Christian