alt Hacker NewsBetter fill those files with random bytes, to ensure the filesystem doesn’t apply some “I don’t actually have to store all-zero blocks” sparse-file optimization. To my knowledge no non-compressing file system currently does this, but who knows about the future.
Replies
freedomben • today at 2:12 PM
Yep, btrfs will happily do this to you. I verified it the hard way
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ape4 • today at 1:49 PM
If I recall correctly:
dd if=/dev/urandom of=/home/myrandomfile bs=1 count=N➕ show 2 replies
XFS, Ext4, btrfs etc… all support sparse files, so any app can cause problems you can try it with:
If you add conv=sparse to the dd command with a smaller block size it will sparsify what you copy too, use the wrong cp command flags and they will explode.Much harder problem than the file system layers to deal with because the stat size will look smaller usually.