Hi, The current qemu max openfile limit is 1024.
This is really to low it you use ceph storage through librbd. For each disk, qemu process is doing 1 tcp connection to each osd. I have trigger a bug this week, a vm with 6 disk and a cluster with 100 osd, At boot vm was working fine, but after some time, vm begin to do random disk access timeout. The number of connection was around 600~700. Also the qemu monitor/qemu-agent was hanging too. Other users have also reported this bug: https://forum.proxmox.com/threads/vm-qmp-command-failed-vm-qmp-command-query-proxmox-support-failed.90160/#post-613685 https://forum.proxmox.com/threads/qemu-crash-with-vzdump.131603/ https://bugzilla.proxmox.com/show_bug.cgi?id=4507#c1 This patch use prlimit command to increase the limit after vm start. I don't have found a way to increase it in the qemu scope directly with LimitNOFILE. Alternative fix is to increase max openfile globally with if vm is launched through gui: /etc/systemd/system.conf.d/max-open-files.conf [Manager] DefaultLimitNOFILE=524289:524289 if vm is launched through ssh with qm: /etc/security/limits.d/10-max-open-files.conf root - nofile 524289 But maybe users could already have tuned it for containers, so I think it's better to only change limit for qemu process. Alexandre Derumier (1): fix #4507 : increase qemu max openfiles limit PVE/QemuServer.pm | 6 ++++++ 1 file changed, 6 insertions(+) -- 2.39.2 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel