>>> On Wed, 12 Mar 2008 16:21:27 +0100, Hubert Verstraete >>> <hubskml@xxxxxxx> said: [ ... ] hubskml> Regarding the slow write performance on the first hubskml> partition of a partitionable RAID-5 array, actually hubskml> this is not linked with the first partition. This issue hubskml> happens when the partition does not start on a cylinder, This is a kind of basic issue for the use of parity RAID, and has nothing to do (at least directly) with cylinders, or with first partitions. But it manifests itself also with partitions that begin on cylinder 1 (often but not necessarily the first) because of the 63 sector offset, and of course also on logical partitions (same). The detailed reasons (RMW and alignment) have also been recently discussed with graphic examples in a couple of recent threads. hubskml> This symptom doesn't exist on RAID-1. hubskml> Does anyone know why ? Those who have been reading the Linux RAID mailing list know why :-). -- 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
