[systemd-devel] systemd and mysql with large memory pages

[Lennart Poettering]

On Sat, 17.09.11 12:57, Reindl Harald (h.reindl at thelounge.net) wrote:

> with sysv/lsb you could include the follwoing script via "source"
> and hughe TLB in mysqld worked like a charme

Hmpf. Global system settings hidden away in specific services is not a
nice solution I'd say.

> [root at rh:~]$ cat /etc/my.memory.cnf
> # Large-Memory-Pages
> echo 200 > /proc/sys/vm/nr_hugepages
> echo 27 > /proc/sys/vm/hugetlb_shm_group
> echo 2097152 > /proc/sys/kernel/shmall

As mentioned, these three should best be set in /etc/sysctl.d/. That way
they are easily discoverable.

> ulimit -l unlimited
> ulimit -n 30000

Also, as mentioned: set this via LimitXXX= in the unit file. See
systemd.exec(5) for more information.
> _____________
> 
> calling this via "ExecStartPre" does not work

The /proc/sys part should work, as that is a system-wide setting. But
it's not nice and dropping this in /etc/sysctl.d is much nicer.

The ulimit stuff is per-process and hence is not inherited from
ExecStartPre=. Set it in the unit file directlry.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.