> > On 04/03/2013 03:18 PM, Stan Hoeppner wrote: > > > You didn't mention your stripe_cache_size value. It'll make a lot of > > difference. Make sure it's at least 4096. The default is 256. > > I'm not getting it - why would stripe cache size matter in a random > read/write test? If the disks are large enough and the pattern is really > random, the cache should hardly ever be hit (s_c_z = 4096 =^ 16MB cache > per disk, that's 0.01% of disk size for a 160GB SSD). > > I read that Peter confirmed the influence of stripe_cache_size, but I'd > like to understand why it matters in this case. > > Martin I'm very sorry but now i can't confirm anymore that stripe_cache_size helps. My test was to short. With every minute the IOPS decrease. So stripe_cache_size does only help for very short tests. I will provide details in another post. Peter -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
