I've figured-out the root of the problem. It's not a true bug, it's a «feature», resulted from the way usb-creator works.
Architecture assumes using SquashFS (http://en.wikipedia.org/wiki/SquashFS) together with UnionFS (http://en.wikipedia.org/wiki/UnionFS) to create semi-writable compressed file system (explanation of the technique: http://tldp.org/HOWTO/SquashFS-HOWTO/creatingandusing.html#sqwrite). As such, copy on write (http://en.wikipedia.org/wiki/Copy-on-write) used when any file from squashed file system must be rewritten. No wonder this doubles space consumption every time you modify (or just touch) a file from original installation. Also, there's no way to delete these files. Two file storages are mounted through loop devices (http://en.wikipedia.org/wiki/Loop_device) (/dev/loop0, /dev/loop1) so you can see all newly created additional files by mounting /dev/loop1. Hence, it seems that installations made with usb-creator are good for small flash drives (because of the SquashFS usage), but running update manager with SquashFS is not such a brilliant idea (because this may require much more space comparing with direct installation, and can create problems resulted from inability to delete files). So if you want to create installation to update it later, it's better to avoid using usb-creator and perform direct setup to flash-drive. As for usb-creator, maybe we should provide a choice to avoid SquashFS usage and to install the whole system on a writable destination. -- free space disappearing on live-usb https://bugs.launchpad.net/bugs/302703 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
