Roch Bourbonnais Wrote: ""100% random writes produce around 200 IOPS with a 4-6 second pause around every 10 seconds. "
This indicates that the bandwidth you're able to transfer through the protocol is about 50% greater than the bandwidth the pool can offer to ZFS. Since, this is is not sustainable, you see here ZFS trying to balance the 2 numbers." When I have tested using 50% reads, 60% random using iometer over NFS, I can see the data going straight to disk due to the sync nature of NFS. But I also see writes coming to a stand still every 10 seconds or so, which I have attributed to the ZIL dumping to disk. Therefore I conclude that it is the process of dumping the ZIL to disk that (mostly?) blocks writes during the dumping. I do agree with Bob and others that suggest making the size of the dump smaller will mask this behavior, and that seems like a good idea, although I have not yet tried and tested it myself. -Scott -- This message posted from opensolaris.org _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
