Hi, I have problem to run postgresql on ubuntu 24.04 server with huge_pages = on. My instance have 8GB ram and 2 vcpus (t3a.large). My configuration is:
max_connections = 1000 superuser_reserved_connections = 3 shared_buffers = 1960MB effective_cache_size = 5881MB huge_pages = on temp_buffers = 32MB max_prepared_transactions = 100 work_mem = 1MB maintenance_work_mem = 392MB max_stack_depth = 4MB dynamic_shared_memory_type = posix archive_mode = on max_wal_senders = 10 wal_sender_timeout = 0 min_wal_size = 4GB max_wal_size = 16GB wal_level = logical checkpoint_timeout = 15min checkpoint_completion_target = 0.9 In my sysct.conf I have: vm.overcommit_memory=2 vm.overcommit_ratio=50 vm.vfs_cache_pressure=50 vm.dirty_background_ratio=10 vm.dirty_ratio=40 fs.nr_open=10000000 fs.file-max=10000000 vm.nr_hugepages=980 vm.hugetlb_shm_group=1010 my huge meminfo looks: cat /proc/meminfo | grep -i huge AnonHugePages: 0 kB ShmemHugePages: 0 kB FileHugePages: 0 kB HugePages_Total: 980 HugePages_Free: 980 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB Hugetlb: 2007040 kB When I start postgres instance I get error: May 07 10:56:32 pg1 pg_ctl[16753]: server starting May 07 10:56:32 pg1 systemd[1]: Started postgres-17.4-local.service - PostgreSQL 17.4 database local server. May 07 10:56:35 pg1 pg_ctl[16756]: 2025-05-07 10:56:35.826 CEST [16756] - [ - - ] [] : XX000FATAL: could not map anonymous shared memory: Cannot allocate memory May 07 10:56:35 pg1 pg_ctl[16756]: 2025-05-07 10:56:35.826 CEST [16756] - [ - - ] [] : XX000HINT: This error usually means that PostgreSQL's request for a shared memory segment exceeded available memory, swap space, or huge pages. To reduce the request size (currently 2204106752 bytes), reduce PostgreSQL's shared memory usage, perhaps by reducing "shared_buffers" or "max_connections". May 07 10:56:35 pg1 pg_ctl[16756]: 2025-05-07 10:56:35.826 CEST [16756] - [ - - ] [] : 00000LOG: database system is shut down May 07 10:56:35 pg1 systemd[1]: postgres-17.4-sdx.service: Main process exited, code=exited, status=1/FAILURE May 07 10:56:35 pg1 systemd[1]: postgres-17.4-sdx.service: Failed with result 'exit-code'. May 07 10:56:35 pg1 systemd[1]: postgres-17.4-sdx.service: Consumed 3.493s CPU time, 2.8M memory peak, 0B memory swap peak. When I comment #huge_pages=on in configuration postgresql started without problems. Can someone tell me where is the problem? Regards Bogdan
