Memory concerns

General Discussions
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1

Hi, we have mender running on imx6ull with only 512M ram and rom.
I would like to understand the memory used by Mender (flash and ram) to make sure we dont have any looming issues.

1> %VSZ reports 170% (log below) usage while free -m reports we are system is using half available. Should I be concerned over this figure?
2> How can I check the total size of the mender usage in flash? I.E when Mender holds the two A/B images during or after update process? This is to check and we wont hit memory issues for future updates - our mender images are <100M but I know its compressed.

PID PPID USER STAT VSZ %VSZ %CPU COMMAND
1263 2 root IW 0 0% 0% [kworker/0:0]
205 1 root S 844m 170% 0% /usr/bin/mender -daemon
341 1 polkitd S 232m 47% 0% /usr/lib/polkit-1/polkitd --no-debug

2

Hi @avrobot,

When doing full image updates, using the dual A/B approach, the incoming image is streamed directly to the inactive partition so you should not have flash storage issues.

I’m not sure about the VSZ report. @kacf any thoughts?

Drew

3

VSZ is not a good measure of memory usage. This is only reporting mapped address space, and not actually used memory, and it is common that VSZ is high. RES or RSS would be better, but they are not included in your output apparently, and even these are not entirely accurate.

The client will of course allocate various smaller buffers during an update, but the “main” working buffer is only around 1MiB, regardless of how big the update is.