On Nov 2, 2009, at 10:15 AM, "Flaherty, Patrick" pflaherty@wsi.com wrote:
If you are a good little doobie, check with your san admin to see if you need to change your starting block alignment. If he looks at you funny, take everything the man says to you with a grain of salt for the rest of your life.
Always hedge your bet and start your partitions at 1MB offset, that should cover most chunk sizes.
With LVM make sure you build into the PVs the offset. I believe the metadata is 128K and the first LV is an additional 64K offset, making the data start at 192K. Fine if your stripe chunk size is 64K, but to cover all the possible chunk sizes make the metadata size 1MB minus 64K during pvcreate. I also set metadatacopies to 2 so there is a backup.
-Ross