Timeline for Do executables in different containers share shared objects that are define in the same common image layer?
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11 events
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| Jul 22, 2024 at 15:51 | comment | added | Philip Couling | @A.G This one keeps throwing me surprises. I've just worked through some basic checks and it seems the docker documentation mentioning hard links is wrong. It doesn't hard-link the files but sets up a multi-layer overlay. I also note that docker claims that cache is shared: docs.docker.com/storage/storagedriver/overlayfs-driver/… I've not successfully found a reason for yours seeing otherwise. | |
| Jul 22, 2024 at 14:41 | comment | added | A.G | I am quite new to this, but these are the findings. When inspecting the /var/lib/containers/**/overlay, I see the folder "l" with all the simlinks to the individual layers. Also, the driver is overlay (according to the documentation: In Docker, there were options to use overlay or overlay2 drivers, but Podman treats these as interchangeable to mean overlay2) and the Backing Filesystem is xfs (same in host). I expected with this setup that page caching is supported. Is it possible that the free command gives misleading results (although I use the same in my non-container setup)? | |
| Jul 22, 2024 at 9:50 | comment | added | Philip Couling | I think the question is going to need further details. Have you investigated the way podman composites its images on disk? IE have you checked files are hard linked between layers as docker does? Also what’s you lt host filesystem? docs.docker.com/storage/storagedriver/btrfs-driver | |
| Jul 22, 2024 at 9:30 | comment | added | A.G | Thanks for the extensive reply. The experiment I run involves monitoring the memory with free -m -s 2 and running the two processes first on the host os and then on separate containers, which have the same base layer with the .so. When running in the host OS, the free memory is decreased by the amount of the shared library only once, whereas in containers it's decreased twice. And I see an equivalent increase in the cache. I realized that the container management tool is podman, not docker (sorry for the incorrect tag). What configuration options should I check? The storage driver is Overlay. | |
| Jul 22, 2024 at 6:24 | history | edited | muru | CC BY-SA 4.0 | markdown hr |
| Jul 22, 2024 at 6:12 | history | edited | Philip Couling | CC BY-SA 4.0 | added 137 characters in body |
| Jul 22, 2024 at 5:34 | history | edited | Philip Couling | CC BY-SA 4.0 | added 523 characters in body |
| Jul 22, 2024 at 2:51 | history | edited | Philip Couling | CC BY-SA 4.0 | added 274 characters in body |
| Jul 22, 2024 at 2:42 | history | edited | Philip Couling | CC BY-SA 4.0 | added 274 characters in body |
| Jul 21, 2024 at 18:08 | history | edited | Philip Couling | CC BY-SA 4.0 | added 506 characters in body |
| Jul 21, 2024 at 17:57 | history | answered | Philip Couling | CC BY-SA 4.0 |