In order to test that our systems correctly detect that they are running out of space, we just need large files on the disk where we do not care about their content at all. At the moment we use dd if=/dev/zero [...]
to create them which takes awfully long especially when writing multiple hundreds of gigabytes to consumer grade SATA disks.
Is there a way to speed this up? I'm thinking of just writing the information that the file exists to the file system table without writing the content of the file, ending up with a huge file containing whatever was written on the disk before.
fallocate
may be what you are looking for.fallocate
definitely does what I need, so clearly a duplicate. Thanks, @Takkat