On Tue, Aug 21, 2012 at 04:07:54PM +0100, Karl E. Jorgensen wrote: > Hi > > On Tue, Aug 21, 2012 at 03:45:35PM +0100, David Cho-Lerat wrote: > > Hi list, > > > > this might be a newbie question, but can anyone tell me > > why "du" and "df" don't seem to agree : > > > > server:~# df -h /var > > Filesystem Size Used Avail Use% Mounted on > > /dev/mapper/vg00-var 5.0G 4.1G 624M 87% /var > > server:~# du -h -s /var > > 1.6G /var > > > > ("/var" is on a partition of its own.) > > FYI: I always use the "-x" flag on du too, as this will not recurse down > other mounted file systems - e.g. if you have /var/cache on a separate > logical volume. > > > "du" says 1.6G are used, while "df" reports 4.1G. Any idea why ? > > "du" will only be reporting disk usage by files and directories it can > find. It will not report overhead by the filesystem itself. > > In your case, the discrepancy is too big (1.6G vs 4.1G) to be > explained by this... > > A couple of possibilities: > > - Deleted files which are open: When a file is deleted, the space is > usually freed immediately. UNLESS the file is open, in which case > the space will not be freed until whatever-has-it-open closes it. > > - Other mountpoints: If you have lots of files in a subdirectory > (e.g. /var/cache) and then mount another file system on /var/cache, > you cannot reach the original contents of /var/cache - and this will > then be invisible to "du"... > > > > > I know some amount of space is supposed to be "reserved for the > > super-user", but that's typically around 5%, right ? > > Around that percentage, yes. But neither du nor df takes this into > account. > > > By the way, is there a command to see how big this reserved space > > actually is on a given partition/disk ?
Correction: To find out the reserved-for-root space: I don't know. Unfortunately, I completely misread your question previously.... -- Karl E. Jorgensen -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20120821151913.GJ5905@hawking