Re: How to configure the hugepages group in Debian?

[Reco <recoverym4n@enotuniq.net>]

	Hi.

On Tue, May 07, 2019 at 01:12:47PM +0200, Mikhail Morfikov wrote:
>    #  mount | grep -i huge
>    hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
> 
> I don't have any fstab entries that would allow to mount /dev/hugepages . 
> So something is mounting it automatically, but I couldn't find any info 
> what that would be.

This particular systemd part is called dev-hugepages.mount.


> It's not really a problem what and where mounts the resource, but I 
> wanted to configure the group that can be set via the 
> "vm.hugetlb_shm_group" sysctl parameter. There's info on the Debian wiki 
> how to do this, and I wanted to add the following entry to the 
> /etc/fstab file in order to configure the group:
> 
>     hugetlbfs /dev/hugepages hugetlbfs rw,relatime,pagesize=2M,mode=1770,gid=5555 0 0
> 
> But this doesn't really work. I mean, those mount options aren't 
> set or are reset. So how to configure this thing?

By following the usual way of overriding systemd's unit (pagesize=2M is
redundant on i386/amd64 and is harmful on other arches):

mkdir /etc/systemd/system/dev-hugepages.mount.d

cat > systemd/system/dev-hugepages.mount.d/override.conf << EOF
[Mount]
Options=mode=1770,gid=5555
EOF

systemctl daemon-reload && systemctl restart dev-hugepages.mount

Reco