[Ocfs2-users] What is the overhead/disk loss of formatting an ocfs2 filesystem?

[Jerry Smith]

Good afternoon,

I have an OEL 6.3 box with a few ocfs2 mounts mounted locally, and was 
wondering what I should expect to lose via formatting etc from a disk 
usage standpoint.

-bash-4.1$ df -h | grep ocfs2
/dev/dm-15             12G  1.3G   11G  11% /ocfs2/redo0
/dev/dm-13            120G  4.2G  116G   4% /ocfs2/software-master
/dev/dm-10             48G  4.1G   44G   9% /ocfs2/arch0
/dev/dm-14            2.5T  6.7G  2.5T   1% /ocfs2/ora01
/dev/dm-11            1.5T  5.7G  1.5T   1% /ocfs2/ora02
/dev/dm-17            100G  4.2G   96G   5% /ocfs2/ora03
/dev/dm-12            200G  4.3G  196G   3% /ocfs2/ora04
/dev/dm-16            3.0T  7.3G  3.0T   1% /ocfs2/orabak01
-bash-4.1$


For example ora04 is 196GB total, but with zero usage it shows 4.3GB used:

[root at oeldb10 ~]#df -h /ocfs2/ora04
Filesystem            Size  Used Avail Use% Mounted on
/dev/dm-12            200G  4.3G  196G   3% /ocfs2/ora04
[root at oeldb10 ~]#find /ocfs2/ora04/ | wc -l
3
[root at oeldb10 ~]#find /ocfs2/ora04/ -exec du -sh {} \;
0    /ocfs2/ora04/
0    /ocfs2/ora04/lost+found
0    /ocfs2/ora04/db66snlux


Filesystems formatted via

mkfs -t ocfs2 -N 16 --fs-features=xattr,local -L ${device} ${device}

Mount options

[root at oeldb10 ~]#mount |grep ora04
/dev/dm-12 on /ocfs2/ora04 type ocfs2 
(rw,_netdev,nointr,user_xattr,heartbeat=none)

Thanks,

--Jerry