[SOLVED] IO delay when an external drive is mounted

[ove90]

Good morning everyone and thanks in advance for your support,

I'm using a datastore on an external usb connected drive, to have offset backup copies. Everything works fine, but I noticed that when the disk is connected and mounted I have IO delay between 0.50-0.80, if the disk is not mounted the IO delay is always at 0. I have other PBS instances with the same system and I have IO delay always 0 with external disk mounted or not. I hope you can help me understand.

proxmox-backup: 2.4-1 (running kernel: 5.15.107-2-pve)
proxmox-backup-server: 2.4.1-1 (running version: 2.4.1)
pve-kernel-5.15: 7.4-3 pve-kernel-5.15.107-2-pve: 5.15.107-2
pve-kernel-5.15.102-1-pve: 5.15.102-1
ifupdown2: 3.1.0-1+pmx3
libjs-extjs: 7.0.0-1
proxmox-backup-docs: 2.4.1-1
proxmox-backup-client: 2.4.1-1
proxmox-mail-forward: 0.1.1-1
proxmox-mini-journalreader: 1.2-1
proxmox-offline-mirror-helper: not correctly installed
proxmox-widget-toolkit: 3.6.5
pve-xtermjs: 4.16.0-1
smartmontools: 7.2-pve3
zfsutils-linux: 2.1.11-pve1

 

[ove90]

I add the package version of another PBS instance where the problem does not occur

proxmox-backup: 2.4-1 (running kernel: 5.15.107-1-pve)
proxmox-backup-server: 2.4.1-1 (running version: 2.4.1)
pve-kernel-5.15: 7.4-2 pve-kernel-5.15.107-1-pve: 5.15.107-1
pve-kernel-5.15.102-1-pve: 5.15.102-1
ifupdown2: 3.1.0-1+pmx3
libjs-extjs: 7.0.0-1
proxmox-backup-docs: 2.4.1-1
proxmox-backup-client: 2.4.1-1
proxmox-mail-forward: 0.1.1-1
proxmox-mini-journalreader: 1.2-1
proxmox-offline-mirror-helper: not correctly installed
proxmox-widget-toolkit: 3.6.5
pve-xtermjs: 4.16.0-1
smartmontools: 7.2-pve3
zfsutils-linux: 2.1.11-pve1

 

[dcsapak]

a low io delay is not concerning in itself, maybe there are some processes accessing that disk? (check e.g. with lsof/iotop/atop/etc.)
maybe the one disk is just a bit slower than the other one?

 

[ove90]

a low io delay is not concerning in itself, maybe there are some processes accessing that disk? (check e.g. with lsof/iotop/atop/etc.)
maybe the one disk is just a bit slower than the other one?

Hi Dominik, thanks for your reply.
Today I did other tests on a new hardware, the result was the same, but I noticed that after a few hours the I/O normalized. Probably after creating the datatstore some process was still being completed. Thank you for your time.
Best regards