When I run df -h I get the following

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3             809G  753G   14G  99% /

But Size - Used is not even close to Avail (809-753 = 56 and it shows 14)

How is that possible? How much space do I really have left?


Usually there is some "reserved" space for superuser (sic), and then there is the fs overhead (i-node tables, etc). Depends on the filesystem.

ext2/3/4 has a default reserve of 5% for uid0 (-m) depending on the usage-type (-T) i-node space is pre-allocated - see df -ih

I'd say the 14G are really available, but there may be 40G of reserve and say 100MB of i-nodes, which would pretty much add up. #ymmw

  • 40GB of reserve, what does that mean? – Noam Jul 7 '14 at 7:48
  • only the root can use it. – rogerovo Jul 7 '14 at 7:49
  • 1
    if you have the ext4 fs, check man tune2fs where the reserved space can be changed (i-nodes can be set only while formatting) – rogerovo Jul 7 '14 at 7:53
  • Is that something I can verify / configure? I'm pretty sure a couple of days ago it did add up (and didn't change any config) – Noam Jul 7 '14 at 7:54
  • sometimes the filesystem totals lag if a big amount of files and/or space is freed up. But not couple of days... – rogerovo Jul 7 '14 at 8:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.