Cut'n'paste from a tutorial I'm writing right now: Check with lsof if there are any very large files that are already deleted but are still open by some processes. # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 32M 153M 18% /boot # dd if=/dev/zero of=testfile bs=1024000 count=50 50+0 records in 50+0 records out 51200000 bytes (51 MB) copied, 0.370919 s, 138 MB/s # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 81M 104M 44% /boot # vi testfile <wait till vi comes up, then crtl-z and bg the process> # rm testfile # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 81M 104M 44% /boot < quit vi> # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 32M 153M 18% /boot Also verify that your fs doesn't have a insane root reserved space set. # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 32M 153M 18% /boot # tune2fs -m 50 /dev/md0 tune2fs 1.41.4 (27-Jan-2009) Setting reserved blocks percentage to 50% (102368 blocks) # df -h . Filesystem Size Used Avail Use% Mounted on /dev/md0 194M 32M 63M 34% /boot THere are of course other reasons but those two are a common problem. Peter. On Wednesday 30 September 2009 16:59:25 Ryan Pugatch wrote: > Hi all, > > Curious issue.. looking in to how much disk space is being used on a > machine (CentOS 5.3). When I compare the output of du vs df, I am > seeing a 12GB difference with du saying 8G used and df saying 20G used. > > # du -hcx / > 8.0G total > > # df -h / > Filesystem Size Used Avail Use% Mounted on > /dev/xvda3 22G 20G 637M 97% / > > I recognize that in most cases du and df are not going to report the > same but I am concerned about having a 12GB disparity. Does anyone have > any thoughts about this or reason as to why there is a big difference? > I have read a few articles online about it and none have really shown > such a large difference. > > Thanks > > > > Ryan Pugatch > Systems Administrator, TripAdvisor > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos >