[linux-lvm] Re: LVM2 stripe performance

[thornber at redhat.com]

On Mon, Apr 05, 2004 at 02:29:19PM -0700, Dave Olien wrote:
> 
> I'm running tiobench on an LVM2 striped logical volume.  I'm  comparing
> the LVM2 striping performance with a similar striping configuration
> using a hardware RAID controller.
> 
> With hardware RAID, I'm able to get about 66 megabytes per second on
> sequential writes, and 52 megabytes per second with random writes.
> 
> With LVM2, I can get only 23 megabytes per second with either random
> or sequential writes.
> 
> Read performance on LVM is about 10% less than with hardware RAID.
> e.g. with 48 threads, hardware RAID sequental reads are 105 megabytes
> per second, LVM2 RAID sequential reads are 95 megabytes per second.
> 
> This is using an ext2 file system, mounted with noatime.
> 
> I think I recall seeing email with similar problems to this on this
> mail list.  If I recall, the cause had to do with ordering of requests
> submitted to disk.
> 
> Has there been any work to address this?

Try the latest -mm kernel

- Joe