Question Debian - Custom - swap memory

[Teal_cfr]

Server operating system version

Debian 10.13

Plesk version and microupdate number

Plesk Obsidian 18.0.49 Update #2

Hi,

I have 2 server :

One dedicated running on Ubuntu 20.04.5 LTS with 125.71 GB of memory and 512.00 MB of swap memory (used at 20%) : this one hosting 6 websites

One is a VPS on cloud services on Debian 10.13 with 30 GB of memory and 1GB of Swap memory (used at 100%) : this hosting 14 websites

My question is mainly on the second server.

I would like to increase the swap memory by following this : Swap - Debian Wiki

But when I run this command, nothing happen

root@:~# swapon -a
root@:~#

Plesk running on sda1

root@:/# cat /proc/partitions
major minor #blocks name

8 0 1048576000 sda
8 1 1048574959 sda1

So if I run this command i get :

root@:/# swapon /dev/sda1
swapon: /dev/sda1: read swap header failed
root@:/#

And then I checked this file, but not sure about the details of it :

# /etc/fstab: static file system information.
UUID=af5f8c82-a495-40e0-b3e6-f361abeec5a4 / ext4 errors=remount-ro 0 1

//swapfile none swap sw 0 0

I would try to increase the swap memory at least to 4 194 304 kilobytes

 

[scsa20]

This isn't a Plesk thing as this is all OS based.

With that said, depending on who you use for the VPS it could be as easy as just making the adjustment through the portal (Linode lets you adjust the swap through the portal itself and it does everything for you) or you can follow How to Add Swap Space on Debian 10 Linux as this article looks to be more correct for Debian 10.

 

[Teal_cfr]

Ok thanks for information

But how to edit /swapfile when is inuse by the system

and without affecting all the production vhost

 

[scsa20]

Have you tried following the instructions that I've linked?

 

[Teal_cfr]

Yes of course with this result

fallocate: fallocate failed: Text file busy

But ok I guess something like this will help me

sudo swapoff -a

 

[mow]

I would like to increase the swap memory by following this : Swap - Debian Wiki

No, you didn't follow that. You neither created a new partition nor a new swapfile to prepare with mkswap and then use with swapon.

But when I run this command, nothing happen

Plesk running on sda1

Be glad it didn't work, otherwise you would have overwritten your OS partition.

But anyway, that there is no swap entry in your fstab means that it is configured on the host. Nothing you can do about it from inside your vps.
(And that is good, because it is one thing to use swap when your physical RAM is full to prevent the host from killing stuff to free RAM, but another to use swap and steal IO bandwidth from the other VPSes just because your assigned RAM is full. The swap you have now is probably on a ram disk and not on physical storage and only there because some software doesn't react well to there not being any swap.)

 

[Teal_cfr]

Thanks to @scsa20 by following the tutorial for Debian 10, then i used sudo swapoff -a and swapon to restart and take the new configuration of 4Go.
I also adjust swappiness value to 40, since there is many vhost running on this VPS.

And @mow it's look like that I can configure on the host.