I have always kept shared-memory on disk. Not even an NVMe, just a regular SATA disk on RAID0. Disk usage never goes above 5%, though I'm sure there may be spikes. Never had any issues thus far.
My RAM usage has never exceeded 2 GB.
I do have a backup node with NVMe testing AppBase 0.19.4. Tested /dev/shm, couldn't think of a single benefit, so I'll stick with NVMe for now. After NVMe comes Optane. Using RAM seems a long, long way away.
Of course, it's a different story for a full node.
Yikes, I'm not sure it's reliable to run it on regular HDD. Is that your backup node? Check your latencies, I bet you're hitting very high numbers every once in a while (i.e. will cause missed blocks).
Short spikes are fine ;-) I hope someone with full node will share best practices ;-) I would love to read about the configuration, requirements and daily issues. ;-)
Do you remember how long is the replay when shared file is on a disk?
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