[SOLVED] vzdump causing swap usage overtime

[rcp_]

Hello,

I'm currently facing a strange behavior while Proxmox executes backup(vzdump.)

When Proxmox starts backup, it also uses swap space, even if there is free RAM, anyone has any idea why?

swappiness already changed to 10.

proxmox-ve: 7.1-1 (running kernel: 5.13.19-6-pve)
pve-manager: 7.1-10 (running version: 7.1-10/6ddebafe)
pve-kernel-helper: 7.1-13
pve-kernel-5.13: 7.1-9
pve-kernel-5.4: 6.4-12
pve-kernel-5.13.19-6-pve: 5.13.19-14
pve-kernel-5.13.19-4-pve: 5.13.19-9
pve-kernel-5.4.162-1-pve: 5.4.162-2
ceph-fuse: 14.2.21-1
corosync: 3.1.5-pve2
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown: residual config
ifupdown2: 3.1.0-1+pmx3
libjs-extjs: 7.0.0-1
libknet1: 1.22-pve2
libproxmox-acme-perl: 1.4.1
libproxmox-backup-qemu0: 1.2.0-1
libpve-access-control: 7.1-6
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.1-3
libpve-guest-common-perl: 4.1-1
libpve-http-server-perl: 4.1-1
libpve-storage-perl: 7.1-1
libqb0: 1.0.5-1
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 4.0.11-1
lxcfs: 4.0.11-pve1
novnc-pve: 1.3.0-2
proxmox-backup-client: 2.1.5-1
proxmox-backup-file-restore: 2.1.5-1
proxmox-mini-journalreader: 1.3-1
proxmox-widget-toolkit: 3.4-7
pve-cluster: 7.1-3
pve-container: 4.1-4
pve-docs: 7.1-2
pve-edk2-firmware: 3.20210831-2
pve-firewall: 4.2-5
pve-firmware: 3.3-6
pve-ha-manager: 3.3-3
pve-i18n: 2.6-2
pve-qemu-kvm: 6.1.1-2
pve-xtermjs: 4.16.0-1
pve-zsync: 2.2.2
qemu-server: 7.1-4
smartmontools: 7.2-pve2
spiceterm: 3.2-2
swtpm: 0.7.1~bpo11+1
vncterm: 1.7-1
zfsutils-linux: 2.1.2-pve1

Best regards.

 

[fiona]

Hi,
likely not related to the issue, but Proxmox VE 7.1 is nearly two years old, I suggest you upgrade to at least 7.4: https://pve.proxmox.com/wiki/Package_Repositories

When Proxmox starts backup, it also uses swap space, even if there is free RAM, anyone has any idea why?

How much free RAM? Do you have a concrete issue with it? If certain pages haven't been used in a long time, the might get swapped out, usually there's nothing wrong with that.

 

[leesteken]

When Proxmox starts backup, it also uses swap space, even if there is free RAM, anyone has any idea why?

I've seen this behavior in the past when VMs (on ZFS) have their Cache set to Write Back, but not recently.

 

[rcp_]

Hi,
likely not related to the issue, but Proxmox VE 7.1 is nearly two years old, I suggest you upgrade to at least 7.4: https://pve.proxmox.com/wiki/Package_Repositories


How much free RAM? Do you have a concrete issue with it? If certain pages haven't been used in a long time, the might get swapped out, usually there's nothing wrong with that.

Hi, Fiona.

Thanks for your reply. Yes, Proxmox VE 7.1 is old, and I'm considering the upgrade.

At this moment the server has nearly 30 GB of free RAM.

Best regards.

 

[rcp_]

I've seen this behavior in the past when VMs (on ZFS) have their Cache set to Write Back, but not recently.

Hi Leesteken,

I appreciate your message.

Yes, I've seen a few suggestions about VM on ZFS, but I'm not using ZFS, and cache mode is DirectSync, previously I was using No cache, but, the behavior is the same.

I think I will try to upgrade and see if anything changes.

Best regards.

 

[rcp_]

Hi,

I will close this thread, I just adjusted the Zabbix trigger, as Fiona said, swap usage is not necessarily a problem.

Thanks all.