All Disk IO shows up as reads in the summary, but iostat shows writes (containers only)

[Boing]

When opening the summary of a container, in the "Disk IO" section I see only reads, but if I check iostat I see that they are actually writes, not reads.

The container in question has its disk on /dev/sda:

This also happens on other containers.
What could be the problem?

Thank you.

root@proxmox:~# pveversion -v
proxmox-ve: 7.0-2 (running kernel: 5.11.22-4-pve)
pve-manager: 7.0-11 (running version: 7.0-11/63d82f4e)
pve-kernel-5.11: 7.0-7
pve-kernel-helper: 7.0-7
pve-kernel-5.4: 6.4-4
pve-kernel-5.11.22-4-pve: 5.11.22-9
pve-kernel-5.11.22-3-pve: 5.11.22-7
pve-kernel-5.4.124-1-pve: 5.4.124-1
pve-kernel-5.4.106-1-pve: 5.4.106-1
ceph-fuse: 14.2.21-1
corosync: 3.1.5-pve1
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown: residual config
ifupdown2: 3.1.0-1+pmx3
ksm-control-daemon: 1.4-1
libjs-extjs: 7.0.0-1
libknet1: 1.22-pve1
libproxmox-acme-perl: 1.3.0
libproxmox-backup-qemu0: 1.2.0-1
libpve-access-control: 7.0-4
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.0-9
libpve-guest-common-perl: 4.0-2
libpve-http-server-perl: 4.0-2
libpve-storage-perl: 7.0-11
libqb0: 1.0.5-1
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 4.0.9-4
lxcfs: 4.0.8-pve2
novnc-pve: 1.2.0-3
proxmox-backup-client: 2.0.10-1
proxmox-backup-file-restore: 2.0.10-1
proxmox-mini-journalreader: 1.2-1
proxmox-widget-toolkit: 3.3-6
pve-cluster: 7.0-3
pve-container: 4.0-9
pve-docs: 7.0-5
pve-edk2-firmware: 3.20200531-1
pve-firewall: 4.2-3
pve-firmware: 3.3-1
pve-ha-manager: 3.3-1
pve-i18n: 2.5-1
pve-qemu-kvm: 6.0.0-4
pve-xtermjs: 4.12.0-1
qemu-server: 7.0-14
smartmontools: 7.2-pve2
spiceterm: 3.2-2
vncterm: 1.7-1
zfsutils-linux: 2.0.5-pve1

 

[Boing]

Anyone?

 

[yusuf81]

yes, it's happen on my cluster too. storage on lvm-thin volume. The symptoms is exactly as you said

root@pve2:~# pveversion
pve-manager/7.0-11/63d82f4e (running kernel: 5.11.22-5-pve)
root@pve2:~#

root@pve2:~# pveversion -v
proxmox-ve: 7.0-2 (running kernel: 5.11.22-5-pve)
pve-manager: 7.0-11 (running version: 7.0-11/63d82f4e)
pve-kernel-helper: 7.1-2
pve-kernel-5.11: 7.0-8
pve-kernel-5.11.22-5-pve: 5.11.22-10
pve-kernel-5.11.22-4-pve: 5.11.22-9
ceph-fuse: 15.2.14-pve1
corosync: 3.1.5-pve1
criu: 3.15-1+pve-1
glusterfs-client: 9.2-1
ifupdown2: 3.1.0-1+pmx3
ksm-control-daemon: 1.4-1
libjs-extjs: 7.0.0-1
libknet1: 1.22-pve1
libproxmox-acme-perl: 1.3.0
libproxmox-backup-qemu0: 1.2.0-1
libpve-access-control: 7.0-5
libpve-apiclient-perl: 3.2-1
libpve-common-perl: 7.0-10
libpve-guest-common-perl: 4.0-2
libpve-http-server-perl: 4.0-2
libpve-storage-perl: 7.0-11
libspice-server1: 0.14.3-2.1
lvm2: 2.03.11-2.1
lxc-pve: 4.0.9-4
lxcfs: 4.0.8-pve2
novnc-pve: 1.2.0-3
proxmox-backup-client: 2.0.10-1
proxmox-backup-file-restore: 2.0.10-1
proxmox-mini-journalreader: 1.2-1
proxmox-widget-toolkit: 3.3-6
pve-cluster: 7.0-3
pve-container: 4.0-10
pve-docs: 7.0-5
pve-edk2-firmware: 3.20200531-1
pve-firewall: 4.2-3
pve-firmware: 3.3-2
pve-ha-manager: 3.3-1
pve-i18n: 2.5-1
pve-qemu-kvm: 6.0.0-4
pve-xtermjs: 4.12.0-1
qemu-server: 7.0-14
smartmontools: 7.2-1
spiceterm: 3.2-2
vncterm: 1.7-1
zfsutils-linux: 2.1.1-pve1
root@pve2:~#

 

[Boing]

This is also happening on another Proxmox server on a different configuration, without LVM or LVM-thin.

yes, it's happen on my cluster too. storage on lvm-thin volume. The symptoms is exactly as you said

Are you using LXC containers?

 

[Boing]

The problem is easily reproducible by installing Proxmox 7 and creating an LXC container. I just tried it by installing Proxmox in VMWare Player and creating a CT and a VM inside it, with no additional configuration or editing anything else. Simply installing Proxmox and adding the community repos, then creating a CT.
Running a write intensive command like

fio --name TEST --eta-newline=5s --filename=temp.file --rw=write --size=2g --io_size=10g --blocksize=1024k --ioengine=libaio --fsync=10000 --iodepth=32 --direct=1 --numjobs=1 --runtime=60 --group_reporting

shows up in the summary as a bunch of reads. Doing the same inside a VM, with the same exact config, shows writes.
Surely someone else must've also noticed this issue..right?

 

[vshaev]

Surely someone else must've also noticed this issue..right?

This is for everyone who switched to Proxmox 7. Somewhere on the forum there was an official answer that debian 11 does not allow registering the container record correctly. Or something like that. And, as I understand it, this is not considered as a problem, but rather as a misunderstanding.
Sorry for my English.