On Wed, 19 Mar 2003 at 11:48am, Andy Arvai wrote
> In the next few weeks I will be building a linux server with a large
> (1.2TB) raid array. There will be two 3ware 7850 cards (running
> hardware raid5) and a software raid0 across these two cards. I plan to
> benchmark three different filesystems (ext3, reiser and xfs) to
> determine which performs the best. The main thing I am interested in is
> sequential i/o with large files and I've heard that xfs should be the
> best choice for this. I am wondering if anyone has recommendations for
> mkfs.xfs or mount options to maximize performance in this situation.
During recent testing on a single 3ware card, I found XFS to have twice
the write speed of ext3, with a similar read speed (this is all with
bonnie++ and the default mkfs options (except for log size)). I didn't
test Reiser. If the server has lots of memory, make sure that your kernel
supports HIGH I/O and that you're using 3ware drivers that support it --
it makes a *big* difference. I'm using the RH based XFS 1.2 release
kernel and the 7.5.3 3ware driver set.
I've got another 3ware based system that's similar to yours (two cards
with a software stripe), and I found that increasing the chunk-size of the
stripe increased performance (at the cost of CPU load) -- I'm using 4096k
in production. mkfs.xfs will automatically tune swidth and sunit for the
software stripe.
On the hardware side, make sure your cards are on separate PCI busses.
You'll be bus limited otherwise.
--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University
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