The EXT4 filesystem sounds harmless to me--at least it's not BTRFS. Synology is a popular brand so I imagine someone else is using it with a Pi 5. The NAS appliance here is by QNAP and I mostly don't like it. I've been planning to replace it with a Pi 5 based file server but at least it's reliable.The bad news is that I was little quick claiming complete success. There is a dramatic change and I can certainly transfer a 10GB file with 100% success the first time after I boot. If I continue transfering 10GB files eventually the system will hang. However, the number of files I can transfer successfully is variable. My record to date is 5 files transfered.Amazing! The 16K pages somehow interacted with something in your environment to trigger bad behaviour in the Linux kernel. Since there is a factor 4 difference in page size I'd want to check that 6.5*4=26GB of file transfers are successful before claiming victory.
In my opinion faults like this should be followed up because they can illustrate bugs in the kernel that are difficult to find but affect longtime reliability for many people.
Although I doubt it is a common setup, NVME on a Pi5 to NAS is not unique. The NAS is a synology DSM1819+ running DSM7.2.2 with disks mounted using CIFS . The NVME is running ext4.
To me your Pi 5 hang sounds like a resource leak related to the CIFS layer not releasing pages--the leak is faster with larger pages. Around here every conjecture is vetted by the dog developer who started howling when I related my idea.
I speculated that others don't see the resource leak because it results from a race triggered by the exact timing characteristics of the Synology NAS and local area network. The howling grew louder.
The noise was too much. I desperately switched roles and decided to do the vetting myself. My next idea, take Fido to the vet, immediately quieted things down. Tail again wagging, Fido offered up the advice of downclocking the Pi by 20 percent to see if that makes it stable.
https://www.jeffgeerling.com/blog/2023/ ... berry-pi-5
I silently agreed to this admittedly canine advice and changed the topic by suggesting a walk to see if the microwave towers were covered with snow.
Statistics: Posted by ejolson — Sat Nov 16, 2024 5:42 pm