Messages in this thread | | | Date | Mon, 5 Jul 2004 02:28:15 +0300 (EEST) | From | Mikael Johansson <> | Subject | Re: RAID-0 read perf. decrease after 2.4.20 |
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Hello again!
Finally had time to test this on IDE, "better late than even later"...
On Thu, 18 Dec 2003, Martin Knoblauch wrote:
> > > Just some feedback: > > > > > > echo 511 > /proc/sys/vm/max-readahead > > > > > > brings back the read performance of my 30 disks on 4 controller > > > LVM/RAID0. > > > > Great. > > > > Indeed :-) Just to clarify - the modification of max-readahead was > sufficient to "fix" the observed read performance degradation. I did > not apply (or reverse) anything on top of 2.4.22. > > Actually 255 would have been sufficient, 511 proved to be a small bit > better :-))
The "max-readahead" does not seem to affect IDE-RAID, at least not with the 2.4.27-pre6 I just compiled on two machines. So the problem still exists, read speed on 2.4.20-ac2 is almost twice as fast as on later kernels :-/
Have a nice summer, Mikael J. http://www.helsinki.fi/~mpjohans/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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