On Friday 23 January 2009, Stephen John Smoogen wrote:
On Tue, Jan 20, 2009 at 9:11 PM, Stephen John Smoogen smooge@gmail.com
wrote:
On Tue, Jan 20, 2009 at 6:33 PM, Jerry Geis geisj@pagestation.com wrote:
Hi guys - I'm really looking forward to 5.3 for the potential of ext4. I am moving/copying image files lately 8G file and it is slow. I am hoping that ext4 really speeds that up.
I don't think it will speed things up much. 8GB files are mostly hardware throughput and ext3/4 will actually be slower because the journalling etc are to make it more robust but at a speed cost. You would probably see better speed by going to ext2.
I make it a habit of eating my own words if I screw up. If the results seen on Ubuntu by one test hold up, it might have a large increase in large writes
In my experience write performance for different filesystems is very dependant on the type of hardware. I have raid controllers where the difference between Ext3 and XFS is ~20% and I have those where it is 120%...
(but nothing in large reads).
Read (single thread seq.) is often limited by having a too low read ahead setting. "blockdev --setra 8192" can often push it up to bare metal speed for both Ext3 and XFS. It's important to note that this may not be very optimal for your typical I/O mix (non single thread, non seq.).
/Peter