I have usb keychain with size of 7.5GB and I need to copy file on it with size 7.4GB. But I can't because superblocks consume 0.5GB of space.
How to create low-overhead file system
filesystems
You don't need a file system to write data to a device. You can simply use tar to create an archive that stores your directory structure and all meta data and write that to the device.Writing dataHere sdb is an example of the USB drive on my system, adjust according to your setup.tar cf /dev/sdb <some_directory>Reading dataYou can directly use tar to read the data from the device:tar xf /dev/sdbIn my experiments this always reads the entire block device, not just the data in the tar archive. If you know that your device has 8 GiB but you only saved, say 3 GiB, you can use dd to avoid reading the entire device:dd if=/dev/sdb bs=1M count=3072 | tar xf -Side notesTry to compress the data as much as possible. This might take a long time, but maybe everything fits on a drive with an ordinary filesystem. I would advice to use 7-Zip, it's slow but it has a high compression ratio. Here is an example:7za a -t7z -m0=lzma -mx=9 -mfb=64 -md=32m -ms=on archive.7z <some_directory>