While I am by no means on expert on this, I went through a similar mental exercise previously and came to the conclusion that in order to service a particular read request, zfs may need to read more from the disk. For example, a 16KB request in a stripe might need to retrieve the full 128KB stripe, if only to verify the checksum of the stripe prior to returning 16KB to the OS.
If I have understand it correctly, then the vdev numbers refer to the amount of data returned to the OS to satisfy requests, while the individual disk numbers refer to the amount of disk I/O required to satisfy the requests. Does that make sense? Standard disclaimers apply: I could be wrong, I often am wrong, etc. -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
