Linux Server Error Messages

Likely this is because your runtime environment is inside some type of - Container/VPS Slice/VM.

This type of message normally emits when a Container/VPS Slice/VM having insufficient privilege to effect /var/$user/0 which can probably ignored.

Best answer will come from your hosting company.

Note: If this occurs on a dedicated server (at the machine level), best to do a reboot, as something's likely very wrong.

Could this potentially cause a slowdown on the part of the users?

I have this issue going where users are having a hard time accessing the site.

Sometimes it seems like it is when they first load the site. At other times it is after it has been idle. I'm just trying to track down what is causing the slow down. So when I saw these entries that were intermittent by about 5-7 minutes, it got me wondering if the slowdown could be related to the error.

In a situation such as this getting a full picture of what your system does would helo.
This is to get to the issue versus each expert infers from the error..

Your setup might be under resourced for the use. David's assessment might be correct if your setup matches his learned guess.

Expanding arnold's suggestion.

First item is to determine your runtime environment, so mention whether you're running - bare metal machine, LXD container, Docker container, VPS, VM (like VirtualBox).

Your runtime environment determines debugging sequence.

Sorry for the delayed reply. I had other projects that took me away.

This is a VPS running on a hosted service.
I am running:

Rant: Here goes...

[ ... soap box mode on ... ]

Most hosting providers are incompetent.

1) If they told you the problem you're seeing somehow relates to a "high resource backup" then either they're incompetent with their on infrastructure setup/maintenance.

Or...

2) They're incompetent about the real source of the problem... which likely has nothing to do with backups...

3) Their tech staff is so incompetent, they have no clue how to correctly diagnose + fix this problem, at the machine level... as likely this has to do with a cgroup problem in relation to containers. There are several outstanding bugs related to cgroup + various container systems, which require a 5.4 or higher Kernel be installed, along with latest container code installed - KVM or LXD or etc...

Likely a little of all these.

You can lease high performance dedicated servers in the $5-$100 USD range from OVH, which will actually work.

The down side of using OVH, is you'll be required to admin your own machine.

Since you're working at the command line using direct systemd commands, seems like you either have the technical expertise to admin your own machines or can develop the required expertise rapidly.

If this problem persists... you get no useful assistance from your hosting provider, then might be time to switch over to using OVH or some other dedicated servers.

[ ... soap box mode off ... ]