timeout when accessing backups via gui

[stefandewal]

When logging onto the gui of proxmox ve server and requesting a listing of the backups we mostly get this
communication failure (0)


when retrying it several times it will work.

This is in a cluster on a proxmox ve 8.4.x server.

in what logs can we find any information on this ? i've been searching but cant seem to find anyting.

the backup are stored on a remote licensed proxmox backup server. connectivity is via private lan.

 

[UdoB]

When logging onto the gui of proxmox ve server and requesting a listing of the backups ...

when retrying it several times it will work.

My very first PBS used only rotating rust. First it worked great. After putting a few TB of actual data on it I had exactly that experience. The listing of backups failed with timeout. Trying it immediately again would succeed - because most part of the metadata was already read and stored in Ram.

The reason in my case was just a too-slow storage system. After realizing this I had added some fast metadata devices - and since then the system works. (Meanwhile there were also several optimization in the PBS codebase. I can not judge which detail was the crucial one.)

What I want to say: PBS needs IOPS. With a slow storage system you may get into trouble, but often only later (instead of from-the-start) when the PBS contains already a large amount of data. Then to list the content of a large storage needs to physically move the head of an HDD just too often...

Disclaimer: just guessing... and repeating "common knowledge"

PS: I am talking about metadata only in the above text. Imagine what happens when you start reading the actual data...?

 

[stefandewal]

thanks for the anwser. i understand your question. funny detail: when accessing the gui on a dedicated proxmox ve server (not in cluster but does store back-ups on the proxmox backup server) it works pretty good.

so it could be that indeed the clustert stores many more backups on the backup server then the small dedicated proxmox ve server.

 

[powersupport]

Hi,

In Proxmox VE 8.4, the GUI gets the backup list from the Proxmox Backup Server (PBS).
The “communication failure (0)” usually means a temporary connection or timeout issue to PBS.

You can check logs here:
On Proxmox VE

• /var/log/pveproxy/error.log
• /var/log/syslog
• journalctl -u pveproxy

On Proxmox Backup Server

• /var/log/proxmox-backup/api.log
• /var/log/proxmox-backup/proxy.log

Since it works after retrying, it’s likely a brief network delay, DNS issue, or time sync problem on the private LAN.