Memory and backup tasks

[Daniel.CG]

Hi, everyone

I have a problem with the use of memory in my proxmox. The memory consumption is increasing while a backup task is in progress, and when finalize the backup job, remains high.

I run only 3 containers and no VM in this server (is a Lenovo ST550).

Kernel Version
Linux 4.15.18-7-pve #1 SMP PVE 4.15.18-27 (Wed, 10 Oct 2018 10:50:11 +0200)

PVE Manager Version
pve-manager/5.2-10/6f892b40


root@pve:~# for i in $(lxc-ls -1); do
> lxc-info -n $i
> done
Name: 100
State: RUNNING
PID: 4076
IP: 192.168.0.232
CPU use: 477.73 seconds
BlkIO use: 0 bytes
Memory use: 217.32 MiB
KMem use: 109.19 MiB
Link: veth100i0
TX bytes: 5.55 MiB
RX bytes: 84.90 MiB
Total bytes: 90.45 MiB

Name: 101
State: RUNNING
PID: 4575
IP: 192.168.0.234
CPU use: 20.29 seconds
BlkIO use: 0 bytes
Memory use: 69.14 MiB
KMem use: 6.27 MiB
Link: veth101i0
TX bytes: 603.24 KiB
RX bytes: 60.66 MiB
Total bytes: 61.25 MiB

Name: 102
State: RUNNING
PID: 5253
IP: 10.160.205.1
IP: 192.168.0.231
CPU use: 242.39 seconds
BlkIO use: 0 bytes
Memory use: 60.07 MiB
KMem use: 7.03 MiB
Link: veth102i0
TX bytes: 69.83 MiB
RX bytes: 133.24 MiB
Total bytes: 203.07 MiB

Use of memory:

root@pve:~# free -m
total used free shared buff/cache available
Mem: 64107 12593 24797 73 26716 50727
Swap: 8191 0 8191

There is no VM in use

root@pve:~# qm list
root@pve:~#

The zpool is ok

root@pve:~# zpool status -v
pool: rpool
state: ONLINE
scan: scrub repaired 0B in 0h3m with 0 errors on Tue Oct 30 18:01:09 2018
config:

NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
mirror-0 ONLINE 0 0 0
sdb2 ONLINE 0 0 0
sda2 ONLINE 0 0 0

errors: No known data errors


Thanks in advance

 

[LnxBil]

On a backup run, all files will be read and therefore you will always have these files directly in memory after reading and this is normal.

Do you know this site?
https://www.linuxatemyram.com/

 

[Daniel.CG]

Hi,

It sounds reasonable that the system consumes RAM while performing the backup, but then it should be freeing memory. In this case it does not happen (in other installations of proxmox that I did it works correctly), memory leak occurs and does not release the used RAM again

 

[LnxBil]

Hi,

It sounds reasonable that the system consumes RAM while performing the backup, but then it should be freeing memory. In this case it does not happen (in other installations of proxmox that I did it works correctly), memory leak occurs and does not release the used RAM again

RAM that is used for caching is never freed automatically, it is reused when needed in a LRU manner. Freeing RAM is unnecessary and will slow down your system.