Performance Issues with Plex LXC / Full VM


Nov 18, 2019

First my host hardware:

Dell R410
2 x E5620 @ 2.40 GHz (16 Cores)
32 GB Ram
Linux proxmox 5.0.21-5-pve #1 SMP PVE 5.0.21-10 (Wed, 13 Nov 2019 08:27:10 +0100) x86_64

proxmox-ve: 6.0-2 (running kernel: 5.0.21-5-pve)
pve-manager: 6.0-15 (running version: 6.0-15/52b91481)
pve-kernel-helper: 6.0-12
pve-kernel-5.0: 6.0-11
pve-kernel-5.0.21-5-pve: 5.0.21-10
pve-kernel-5.0.15-1-pve: 5.0.15-1
ceph-fuse: 12.2.11+dfsg1-2.1+b1
corosync: 3.0.2-pve4
criu: 3.11-3
glusterfs-client: 5.5-3
ksm-control-daemon: 1.3-1
libjs-extjs: 6.0.1-10
libknet1: 1.13-pve1
libpve-access-control: 6.0-4
libpve-apiclient-perl: 3.0-2
libpve-common-perl: 6.0-8
libpve-guest-common-perl: 3.0-3
libpve-http-server-perl: 3.0-3
libpve-storage-perl: 6.0-11
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve3
lxc-pve: 3.2.1-1
lxcfs: 3.0.3-pve60
novnc-pve: 1.1.0-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.0-9
pve-cluster: 6.0-9
pve-container: 3.0-13
pve-docs: 6.0-9
pve-edk2-firmware: 2.20190614-1
pve-firewall: 4.0-8
pve-firmware: 3.0-4
pve-ha-manager: 3.0-5
pve-i18n: 2.0-3
pve-qemu-kvm: 4.0.1-5
pve-xtermjs: 3.13.2-1
qemu-server: 6.0-16
smartmontools: 7.0-pve2
spiceterm: 3.1-1
vncterm: 1.6-1
zfsutils-linux: 0.8.2-pve2

I get Plex installed without issues and running. After it scans through the files and updates thumbnails, I try to start a movie. It will sit at the selected movie background page and just spin the getting ready indicator circle. I receive the same symptoms whether I use LXC or a full VM. I have the movies on a FreeNAS system that I am mounting via CIFS into the container / VM. My movie library is too large to fit onto the local storage for the Proxmox server, which is why I have been running them off the SMB share from the FreeNAS.

If anyone has any suggestions, I'd be eager to hear them.

After starting Movie watch htop from VM/LXC and open Plex Web Settings and look utilization. I guess that Plex try to Transcode (Had such problem before). Can recommend to make some tmp folder in Proxmox host, not using SMB share for tmp because Plex brings movies from SMB, transcoding and put it back to smb so what is overhead for network performance as I have understood)
Also have a look at iftop, if plex is pulling the file really quick over SMB you could be maxing out the network and it's unable to stream with the remaining bandwidth.


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