I have read some conflicting things regarding the ZFs record size setting. Could you guys verify/correct my these statements:
(These reflect my understanding, not necessarily the facts!) 1) The ZFS record size in a zvol is the unit that dedup happens at. So, for a volume that is shared to an NTFS machine, if the NTFS cluster size is smaller than the zvol record size, dedup will get dramatically worse, since it won't dedup clusters that are positioned differently in zvol records. 2) For shared folders, the record size is the allocation unit size, so large records can waste a substantial amount of space, in cases with lots of very small files. This is different than a HW raid stripe size, which only affects performance, not space usage. 3) Although small record sizes have a large RAM overhead for dedup tables, as long as the dedup table working set fits in RAM, and the rest fits in L2ARC, performance will be good. Thanks, Rob -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
