Debian 9 / Proxmox 5 : memory bug ?

Icar

New Member
Jul 12, 2017
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Hi,

A have a lot of containers (Debian 9) with same problem :

#free -h
total used free shared buff/cache available
Mem: 2.0G 2.8G 147M 3.6G 101M 147M

# wget http://URL/1Gb.file

# free -h
total used free shared buff/cache available
Mem: 2.0G 1.8G 147M 3.6G 101M 147M

ProxMox GUI indicating good value.

Performance's system are very poor because no free memory...

Can anyone help me please ?
Thx

proxmox-ve: 5.0-16 (running kernel: 4.10.15-1-pve)
pve-manager: 5.0-23 (running version: 5.0-23/af4267bf)
pve-kernel-4.10.15-1-pve: 4.10.15-15
pve-kernel-4.10.17-1-pve: 4.10.17-16
libpve-http-server-perl: 2.0-5 lvm2: 2.02.168-pve2
corosync: 2.4.2-pve3 libqb0: 1.0.1-1
pve-cluster: 5.0-12
qemu-server: 5.0-14
pve-firmware: 2.0-2
libpve-common-perl: 5.0-16
libpve-guest-common-perl: 2.0-11
libpve-access-control: 5.0-5
libpve-storage-perl: 5.0-12
pve-libspice-server1: 0.12.8-3
vncterm: 1.5-2
pve-docs: 5.0-9
pve-qemu-kvm: 2.9.0-2
pve-container: 2.0-15
pve-firewall: 3.0-2
pve-ha-manager: 2.0-2
ksm-control-daemon: 1.2-2
glusterfs-client: 3.8.8-1
lxc-pve: 2.0.8-3
lxcfs: 2.0.7-pve2
criu: 2.11.1-1~bpo90
novnc-pve: 0.6-4
smartmontools: 6.5+svn4324-1
 
Same problem with Debian 8 and Ubuntu 17.04

Really strange :

# free -h
Mem: 5.5G

#wget http://URL/1Gb.file

# free -h
Mem: 4.5G

# rm 1Gb.file
# free -h
Mem: 5.5G
 
Last edited:
Well it seems "cached memory" isn't erased.
The problem is that LXC perfs are really bad...

Can i disable cache utilisation ? Any suggestion please ?
 
Thx for your asnwer.
I have no problem with Linux's cache usage. The problem is that cache isn't erased when i need RAM...
If i download a 1 Gb file (and write to disk), memory isn't free until i erase file.
I haven't this problem on physical machines, only in Proxmox.

By the way, proxmox is showing the correct value in Web GUI, but #free in the LXC/VM is very low and system is veeeery slow.
 
I'm sorry buts is a real problem for me...
RAM is never cleared and servers must be rebooted periodically :(

Any suggestion please ?
 
Maybe ZFS is different (Not sure if you use ZFS or LVM or?) because I don't have this problem with Debian 9 container (just tested with downloading 3 x 100 MB files) and free ram with free -h does not change.
 
Thank you for your reply.
With SWAP = 0 all seems ok. I dont know what are impacts...
 
Last edited:

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