On Fri, Jun 20, 2008 at 12:55 PM, Florin Andrei florin@andrei.myip.org wrote:
Anyway, I did a test with the 2.6.18-93.el5.bz444759 kernel and there's no difference: 65 minutes, 27 MB/s. Looks like it doesn't matter which kernel I use, at least for this simple test with dd.
No. Since you're using the driver from 3ware/amcc you are not going to experience this particular performance hit. Only if you're using the stock 3ware driver which is built into the kernel.
As a side note, the artificial benchmark reveals a huge difference between Ext3 and XFS - the latter is much faster when writing. Might be an artifact of some setting (after all, I do use a hardware RAID card). But the difference is very real.
I was planning to use XFS anyway, so I'm not sure if I'll spend too much time troubleshooting Ext3.
I don't think this is some kind of hidden effect of the MWI bug.
Nope. This is just a long-standing performance thing. You can tune ext3 to perform better, but on a 3ware card xfs will win, hands down.