Re: New PG14 server won't start with >2GB shared_buffers

Bear in mind that if you are using systemd to start postgres, then these user limits may not apply.

Th logged in user limits get set by the PAM subsystem, but when systemd starts a subsystem no actual login occurs and PAM is never invoked.

The systemd unit file must have limits set within in.

https://www.freedesktop.org/software/systemd/man/systemd.exec.html

In the [service] section use one of

LimitCPU= Seconds
LimitFSIZE= Bytes
LimitSTACK= Bytes
LimitCORE= Bytes
LimitRSS= Bytes
LimitNOFILE= intenger
LimitAS= Bytes
LimitNPROC= intenger
LimitMEMLOCK= Bytes
LimitLOCKS= intenger
LimitSIGPENDING= intenger
LimitMSGQUEUE= Bytes
LimitNICE= Nice Level
LimitRTPRIO= Realtime Priority
LimitRTTIME= Microseconds

On 2023-02-25 06:55, Chris Hoover wrote:

Ken,

$ id

uid=998(postgres) gid=1003(postgres) groups=1003(postgres),115(ssl-cert)

$ ulimit -a

core file size          (blocks, -c) 0

data seg size           (kbytes, -d) unlimited

scheduling priority             (-e) 0

file size               (blocks, -f) unlimited

pending signals                 (-i) 4128123

max locked memory       (kbytes, -l) 65536

max memory size         (kbytes, -m) unlimited

open files                      (-n) 1024

pipe size            (512 bytes, -p) 8

POSIX message queues     (bytes, -q) 819200

real-time priority              (-r) 0

stack size              (kbytes, -s) 8192

cpu time               (seconds, -t) unlimited

max user processes              (-u) 4128123

virtual memory          (kbytes, -v) unlimited

file locks                      (-x) unlimited

$ sysctl -a | grep shm

kernel.shm_next_id = -1

kernel.shm_rmid_forced = 0

kernel.shmall = 17179869184

kernel.shmmax = 274877906944

kernel.shmmni = 4096

Thanks,

Chris Hoover

Senior DBA

AWeber.com

Cell: (803) 528-2269

Email: chrish@aweber.com

On Feb 25, 2023, at 9:49 AM, Kenneth Marshall <ktm@rice.edu> wrote:

Chris Hoover wrote on 2/25/2023 8:07 AM:

Ron,

Honestly, I grabbed 500MB to get the database up, by this time I
was very frustrated and just wanted it up.  :)  I think I was at
1500MB and it still would not start.  So to save what was left of
my evening out, I just picked 500.

Here is shmall:
kernel.shmall = 17179869184

Thanks,


Chris Hoover
Senior DBA
AWeber.com
Cell: (803) 528-2269
Email: chrish@aweber.com

Hi Chris,

What are your limits set to for the account that the database runs as?

Regards,
Ken

-- 
Evan Rempel                                         250.721.7691
Senior Systems Administrator                     erempel@uvic.ca
Data Centre Services, University Systems, University of Victoria