[Ocfs2-users] ocfs2 vs ext3?

[Andrew (Anything)]

Hi Tao

> echo 'stats'|debugfs.ocfs2 /dev/sdX|grep "Incompat"

I re-read your reply with the Incompat flag check and it made me think to
check what mine were showing.

I found that my format with max-features meant that it wasn't using all the
available features.
Some are probably quite important for performance.

mkfs.ocfs2 -T mail --fs-feature-level=max-features /dev/sda
debugfs.ocfs2 stats was showing:
        Feature Compat: 1 BackupSuper
        Feature Incompat: 272 Sparse ExtendedSlotMap

I downloaded the ocfs2-tools via git, instead of the 1.4.1 source file on
the ocfs website, and reformatted my partition with the following options
(just in case)
mkfs.ocfs2 -T mail --fs-feature-level=max-features
--fs-features=backup-super,sparse,unwritten,inline-data,noxattr /dev/sda
debugfs.ocfs2 stats now shows:
        Feature Compat: 3 BackupSuper JBD2SuperBlock
        Feature Incompat: 2384 Sparse ExtendedSlotMap InlineData MetaECC


Performance is considerably better when tested with bonnie++ -n
25:1024:0:10, probably because of the inline data.
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
files:max            /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec
%CP
before 25:1024:0/10  1721  39 +++++ +++  2655  13  1806  44 +++++ +++  1995
19
before 50:1024:0/10  1645  62   976   8  1586  11  1469  56   120   1   336
5
after  25:1024:0/10  4015  83 +++++ +++  3119  12  3872  80 +++++ +++  1953
13
after  50:1024:0/10  2486  80 99692 100  2737  14  2694  88 83541  98   615
5


Are there any other features im missing that might effect performance?

And what does the incompat flags mean?
I had mistaken them to mean that these features are available but
incompatible with this partition, ie: not used.


Andy..