I am confused with du command because it gives different result for files.
[root@gerrh6-05 sathish]# du -s saravana/admin/sqlnet.ora
4 saravana/admin/sqlnet.ora
[root@gerrh6-05 sathish]# du -h saravana/admin/sqlnet.ora
4.0K saravana/admin/sqlnet.ora
[root@gerrh6-05 sathish]# du -b saravana/admin/sqlnet.ora
65 saravana/admin/sqlnet.ora
[root@gerrh6-05 sathish]# du -bh saravana/admin/sqlnet.ora
65 saravana/admin/sqlnet.ora
[root@gerrh6-05 sathish]# ll -h saravana/admin/sqlnet.ora
-rw-r----- 1 root root 65 May 18 03:47 saravana/admin/sqlnet.ora
Disk usage summary return invalid result(-s gives 4 and -b gives 65), where bytes(-b) return same as ll result.
[root@gerrh6-05 sathish]# du -sh saravana/admin
114M saravana/admin
[root@gerrh6-05 sathish]# du -bh saravana/admin
12K saravana/admin/1/xdb_wallet
7.4K saravana/admin/1/pfile
7.2M saravana/admin/1/test/result/data
7.6M saravana/admin/1/test/result
7.0M saravana/admin/1/test/data
28M saravana/admin/1/test
7.2M saravana/admin/1/adump
4.0K saravana/admin/1/logbook/controlfile_trace
8.0K saravana/admin/1/logbook
4.2K saravana/admin/1/dpdump
35M saravana/admin/1
35M saravana/admin
From above which is correct size of /admin dir 35M or 114M.
Which one I should take?
Note: I am working on a linux machine where I don't have UI.Purpose why I ma looking for this is, I writing a script to taking backup. I should split folders and files based on size limit 4GB. Which one I should take to count.Because the different is large!!
From man du:
--apparent-size: print apparent sizes, rather than disk usage; although the apparent size is usually smaller, it may be larger due to holes in ('sparse') files, internal fragmentation, indirect blocks, and the like
-b, --bytes: equivalent to--apparent-size --block-size=1
So, -b tells you how much data is stored; without it, you get how much disk space is used. Both are "correct size", for different definition of "size".