[Ocfs2-users] OCFS2 benchmark slow concurrent write

[Philipp Wehrheim]

Am Donnerstag, den 14.06.2007, 16:08 -0700 schrieb Sunil Mushran:
> Did you try using a gige interconnect?

No not yet.
Do you think that the network is the bottlenack?
I tried to follow the used network bandwidth with nettop
and the bandwith used was never more than ~4Mbit.

Is there a way to compile the ocfs2 module with special small
file support (e.q. now I guess its more optimized for big files)?
Or can the dlm be tweaked somehow?

I'm mounting the partion now with noatime -> but no speed improve at
all.

> 
> Philipp Wehrheim wrote:
> > Hi everbody,
> >
> > I've just created a test setup for my company with two pc's drbd (0.8.3)
> > primary/primary mode with OCFS2 on top of it. the pc's are running suse
> > 10.2 with kernel 2.6.21.2. the Hardware CPU ~1GHz ~12 MBRam and one NIC
> > (100Mbit).
> >
> > The setup is working quite stable and so I started to make some
> > benchmarks and received some strange results:
> >
> > For the benchmark I used a small C-prog "iotest" that, in a loop, open a
> > file write on line and closes the file again.
> >
> > ---
> > #define LOOPCOUNT 1050620
> > ...
> >   for (i=0; i<LOOPCOUNT; i++) {
> >     if ( (logFD = open (LOGFILE, O_WRONLY|O_CREAT|O_APPEND, 0666)) !=
> > -1) {
> >       write (logFD, logMSG, logLEN);
> >       close (logFD);
> >   }
> > ---
> >
> >
> > 1. write to a ext3-fs
> >
> > 	| per line 	  | for 1050620 lines |
> > hobbes  | 44 nanoseconds  | 47.1 seconds      |
> > struppi | 37 nanoseconds  | 39.3 seconds      |
> >
> >
> > 2. write to a OCFS2-fs single -> only one maschiene at the time
> >
> > 	| per line 	  | for 1050620 lines |
> > hobbes  | 84 nanoseconds  | 88.3 seconds      |
> > struppi | 47 nanoseconds  | 50.1 seconds      |
> >
> >
> > 3. write to a OCFS2-fs into _ONE_ file -> concurrent write from both pcs
> >
> > 	| per line 	   | for 1050620 lines |
> > hobbes  | 113 milliseconds | 119764 seconds    | yes over 33h
> > struppi | 113 milliseconds | 119764 seconds    |
> >
> >
> > 4. write to a OCFS2-fs into two files -> each pc into one file
> >
> > 	| per line 	  | for 1050620 lines |
> > hobbes  | 93,6 nanoseconds  | 98.6 seconds    |
> > struppi | 59,5 nanoseconds  | 62.6 seconds    |
> >
> >
> > So as one can see OCFS2 does quite good but when it comes to concurrent
> > writes into one file it is sloooooowwwwwwww.
> > The question is now:
> >
> > - is there an error in my setup
> > - how can i tune ocfs2
> > - how can i tune dlm
> > - WHERE IS THE OCFS2 DOCU???(no im not talking about colorful powerpoint slides)
> >
> > Thanks in advance
> > Philipp
> >
> >
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> >   
>