Lxc import uses too much RAM

angristan · January 30, 2019, 10:37am

I have had this issue for a while, so I think it is best to report it.

I have a export of a container that is not that big:

stanislas@xps ~> ll notthatbigct.tar.gz
.rw-r--r-- 3,5G stanislas wheel 29 janv. 14:04 notthatbigct.tar.gz

When I import it, it uses an enourmous amount of RAM (more than 10 GB), causing my computer to freeze a bit:

Then it fails:

stanislas@xps ~> lxc import notthatbigct.tar.gz
Importing container: 100% (821.38MB/s)Error: Post http://unix.socket/1.0/containers: EOF

This is an Arch Linux container on Arch Linux, but I had this problem a few months ago on an Ubuntu CT on Ubuntu. LXD is installed from snap.

stgraber · January 30, 2019, 7:56pm

Could you file a bug at https://github.com/lxc/lxd/issues?

angristan · January 30, 2019, 8:49pm

Done: https://github.com/lxc/lxd/issues/5447

I have noticed that the LXD daemon is restarting during the import, probably because of memory usage (no OOM kill though), and thus causing the EOF on the POST request.

angristan · February 19, 2019, 12:43pm

I’m happy to report that https://github.com/lxc/lxd/commit/f18362015da4fe468305a12036a7b624206b9ebe fixes this issue, and as of 3.10 the RAM usage is much lower!