I'm hosting my own Lemmy instance and trying to figure out how to optimize PSQL to reduce disk IO at the expense of memory.
I accept increased risk this introduces, but need to figure out parameters that will allow a server with a ton of RAM and reliable power to operate without constantly sitting with 20% iowait.
Current settings:
# DB Version: 15
# OS Type: linux
# DB Type: web
# Total Memory (RAM): 32 GB
# CPUs num: 8
# Data Storage: hdd
max_connections = 200
shared_buffers = 8GB
effective_cache_size = 24GB
maintenance_work_mem = 2GB
checkpoint_completion_target = 0.9
wal_buffers = 16MB
default_statistics_target = 100
random_page_cost = 4
effective_io_concurrency = 2
work_mem = 10485kB
min_wal_size = 1GB
max_wal_size = 4GB
max_worker_processes = 8
max_parallel_workers_per_gather = 4
max_parallel_workers = 8
max_parallel_maintenance_workers = 4
fsync = off
synchronous_commit = off
wal_writer_delay = 800
wal_buffers = 64MB
Most load comes from LCS script seeding content and not actual users.