This question already has an answer here:
Recently I was running
du -h / on my partition as I was downloading a large file, and noticed that the available space decreased while the used space did not increase (in the last two lines of this output.) None of the new files that are being downloaded are owned by anyone else other than myself.
What would cause this? I have a feeling it is a rounding error, but would that mean that the
Used space is being rounded up while the
Avail space is rounded down? It seems like the free and total bytes are being subtracted but I'm not sure.
alex@server:~/cc-pipermail$ df -h / Filesystem Size Used Avail Use% Mounted on /dev/vda1 20G 8.6G 10G 47% / alex@server:~/cc-pipermail$ df -h / Filesystem Size Used Avail Use% Mounted on /dev/vda1 20G 8.7G 10G 47% / alex@server:~/cc-pipermail$ df -h / Filesystem Size Used Avail Use% Mounted on /dev/vda1 20G 8.7G 9.9G 47% /
For clarification, the used space is 8.7GB, but then the available changes from 10G to 9.9G with the used space not changing.
This question is different from Why is df missing 500MB of available space? because that question is discussing a discrepancy with a volume which has extra inodes allocated, while this question showed that
df did report free space just moments before the file continued to download.