Edward, Thanks for the reply. Good point on platter density. I'ld considered the benefit of lower fragmentation but not the possible increase in sequential iops due to density.
I assume while a 2TB 7200rpm drive may have better sequential IOPS than a 500GB, it will not be double and therefore, if the 500GB's are half price the double spindle count would lead to better overall sequential IOPS (assuming still enough excess space to remove fragmentation benefit and increased usable GB's). Agree? Our IO is random small(4kB) read/write but I expect ZFS to convert the writes to sequential and the L2ARC to intercept a lot of the reads. (assumes low latency, high iop ZIL SLOG device). It basically seems to come down to whether the random reads that miss the cache need lower individual latency or not. Thanks for the pointer on terminology. I had thought that the RAM write cache was also called ARC (in addition to the RAM read cache). -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
