I'm troubleshooting an issue regarding disk size usage in a centOS system (one of the partitions was growing too fast), and I notice one of my directories has 3.1GB:
$ du -hs /var/log/mongodb/
3.1G /var/log/mongodb/
$ df -h /var/log/mongodb/
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg00-log 4.0G 3.7G 324M 93% /var/log
However, when I analyse the directory contents, I realize it only has 1 file, and that file is not that large (2.1GB):
$ ls -larth /var/log/mongodb/
total 3.1G
drwxr-xr-x 2 mongod mongod 24 Jul 2 2019 .
drwxr-xr-x. 22 root root 4.0K May 1 03:50 ..
-rw-r----- 1 mongod mongod 2.1G May 1 08:41 mongod.log
How can this happen?
Stat command:
$ stat /var/log/mongodb/mongod.log
File: ‘/var/log/mongodb/mongod.log’
Size: 2448779949 Blocks: 4880912 IO Block: 4096 regular file
Device: fd08h/64776d Inode: 6291527 Links: 1
Access: (0640/-rw-r-----) Uid: ( 996/ mongod) Gid: ( 994/ mongod)
Access: 2020-05-01 10:02:57.136265481 +0000
Modify: 2020-05-04 10:05:37.409626901 +0000
Change: 2020-05-04 10:05:37.409626901 +0000
Birth: -
Another example in another host:
$ df -kh | grep var
/dev/dm-3 54G 52G 2.1G 97% /var[
$ du -khs /var/
25G /var/
Is this somehow related to the difference between file size and actual space on disk occupied (due to disk blocks)? If so, how can I perform a defragmentation/optimization?
