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"du" & "df" OS commands Report Space Used Differences On ACFS Filesystems. (Doc ID 1384276.1)

Last updated on FEBRUARY 03, 2019

Applies to:

Oracle Database - Enterprise Edition - Version to [Release 11.2]
Information in this document applies to any platform.
***Checked for relevance on 04-Dec-2013***


"du" & "df" OS commands report different ACFS filesystem space usage:

1) The next ACFS filesystem was created and mounted:

[grid@asmgrid ~]$ /sbin/acfsutil info fs
ACFS Version:
flags: MountPoint,Available
mount time: Wed Oct 26 17:57:29 2011
volumes: 1
total size: 102005473280
total free: 101765128192
primary volume: /dev/asm/ebernal-238
flags: Primary,Available,ADVM
on-disk version: 39.0
allocation unit: 4096
major, minor: 252, 121857
size: 102005473280
free: 101765128192
ADVM diskgroup ACFS
ADVM resize increment: 536870912
ADVM redundancy: unprotected
ADVM stripe columns: 4
ADVM stripe width: 131072
number of snapshots: 0
snapshot space usage: 0

[grid@asmgrid ~]$ ls -l /u04acfs
total 64
drwx------ 2 root root 65536 Oct 4 16:00 lost+found
[grid@asmgrid ~]$

2) Then it was populated with a 1 GB file:

[grid@asmgrid ~]$ dd if=/dev/zero of=/u04acfs/1GB_file.dump bs=1048576 count=1024
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 4.03695 seconds, 266 MB/s

[grid@asmgrid ~]$ ls -l /u04acfs/1GB_file.dump
-rw-r--r-- 1 grid oinstall 1073741824 Dec 7 20:13 /u04acfs/1GB_file.dump

3) Then verified the allocated spaced using the "df" OS command:

[grid@asmgrid ~]$ df -hBM /u04acfs
Filesystem 1M-blocks Used Available Use% Mounted on
/dev/asm/ebernal-238 97280M 1277M 96004M 2% /u04acfs

4) And verified the allocated spaced using the "du" OS command:

[grid@asmgrid ~]$ du -h /u04acfs
4.0K /u04acfs/.ACFS/.fileid
4.0K /u04acfs/.ACFS/repl/staging
4.0K /u04acfs/.ACFS/repl/ready
4.0K /u04acfs/.ACFS/repl/processed
4.0K /u04acfs/.ACFS/repl/logs
20K /u04acfs/.ACFS/repl
4.0K /u04acfs/.ACFS/snaps
32K /u04acfs/.ACFS
1.1G /u04acfs
[grid@asmgrid ~]$

5) "df -hBM /u04acfs" reports 1,277 MB used whereas "du -h /u04acfs" reports 1,126.4 MB  (1.1GB) as used.

6) There is a difference of 150.6 MB, since "df -hBM /u04acfs" reports more used space .


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