Cant understand the File system working nature

UNIX Solaris
1

Hi,

We have a filesystem whose usage has gone above 81%, i tried to zip some files in the sub directories but the space is not released in the main file system.

> df -h
Filesystem             size   used  avail capacity  Mounted on
/u01/app               5.8G   4.6G   1.2G    81%    /u01/app
/u01/app/oracle/exp     16G   582M    15G     4%    /u01/app/oracle/exp

Here we have FS /u01/app with size 5.8 GB and /u01/app/oracle/exp with size 16 GB.

So if i delete or zip files in /u01/app/oracle/exp FS usage should reduce in /u01/app right.

Please advice.

2

This might be due to the deleted file still present in a ZFS snapshot.

3

can you please let me know what is ZFS snapshot and how to find the files stored in it.