[Ocfs2-users] ocfs2 slow write performance on Linux 2.6.38

[Sunil Mushran]

What type of writes are these... sequential or random?

On 6/12/2011 5:37 PM, fibreraid at gmail.com wrote:
> Hello all,
>
> I am benchmarking OCFS2 in a single node environment to see how its
> performance stacks up against other Linux file systems. My hardware is
> dual CPU, 6-cores per CPU, 2.4GHz Westmere with 24GB RAM. My system
> has 24 HDD's of which 23 are active drives in a md RAID 5 array with
> 64K chunk size, and one hot-spare. I have a LVM2 volume created out of
> this md array. It is running Linux 2.6.38 kernel.
>
> I am creating the OCFS2 file system as follows:
>
> /sbin/mkfs.ocfs2 -N 2 -M local
> --fs-features=sparse,refcount,xattr,indexed-dirs,discontig-bg,inline-data
> -F /dev/md0/ocfs2max
>
> I am then mounting it as:
>
> /bin/mount /volumes/md0/ocfs2max
>
> I am using fio 1.55 to measure performance. My benchmark script uses
> uncached IO in 4K and 4M block sizes. I am running 8 fio jobs and 512
> IO depth. I am using a 20GB file as the test file for this benchmark.
>
> OCFS2 reads (both at 4M and 4K) are very good...within +-3% of the
> other major Linux file systems. However, 4K writes are substantially
> lower, about half the speed of other Linux FS's.
>
> Can you provide some recommendations on how I can improve the write
> speed with OCFS2? At the current write rate, the trade-off is too
> much, but I really like the other features of OCFS2 so I am hopeful
> that some tuning/tweaking will get the performance up where it needs
> to be.
>
> Thank you very much in advance!
>
> - TG
>
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