Aw: Dracut, dmsquash, and overlays

[Fabian Deutsch]

> Hello there,
> 
> I'm working with F20 and CentOS 7 to create some live booted images.  I'm not looking to do live USB/CD media, but rather boot a server over the network with a kernel, initramfs, and squashfs.  It's working well so far, but I have a filesystem issue that I can't seem to fix.
> 
> My build scripts create a 10GB sparse file and I fill that with an ext4 filesystem.  I package that up into a squashfs as specified in the docs[1].  That boots just fine.
> 
> However, if I attempt to fill the filesystem, it fills and becomes corrupt much earlier than I'd expect.  I've put some log info into a gist[2].
> 
> My expectation is that if I create a 10GB live filesystem and and the system has > 10GB of RAM available, I'd expect that I could store somewhere around 10GB of data in the live filesystem before I run into a full filesystem.  Is that expectation incorrect?  Am I configuring something incorrectly?
> 
> Thanks for taking the time to read this far. :)

Hey,

I am not completely if it is this issue you are seeing, but a squashfs image takes more memory then the image itself, becasue you first need to unsquash (in ram) and the load the fs pages into ram.
Also take a look here: http://dummdida.tumblr.com/post/89051342705/taking-a-look-at-the-rootfs-footprint-of-a-livecd-and-a

- fabian

> [1] https://fedoraproject.org/wiki/LiveOS_image
> [2] https://gist.github.com/major/d4e9f447ab942edd7952
> 
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