As a followup: I ran the same DD test as earlier- but this time I stopped the scrub:
pool0 14.1T 25.4T 88 4.81K 709K 262M pool0 14.1T 25.4T 104 3.99K 836K 248M pool0 14.1T 25.4T 360 5.01K 2.81M 230M pool0 14.1T 25.4T 305 5.69K 2.38M 231M pool0 14.1T 25.4T 389 5.85K 3.05M 293M pool0 14.1T 25.4T 376 5.38K 2.94M 328M pool0 14.1T 25.4T 295 3.29K 2.31M 286M ~# dd if=/dev/zero of=/pool0/ds.test bs=1024k count=2000 2000+0 records in 2000+0 records out 2097152000 bytes (2.1 GB) copied, 6.50394 s, 322 MB/s Stopping the scrub seemed to increase my performance by another 60% over the highest numbers I saw just from the metaslab change earlier (That peak was 201 MB/s). This is the performance I was seeing out of this array when newly built. I have two follow up questions: 1. We changed the metaslab size from 10M to 4k- that's a pretty drastic change. Is there some median value that should be used instead and/or is there a downside to using such a small metaslab size? 2. I'm still confused by the poor scrub performance and it's impact on the write performance. I'm not seeing a lot of IO's or processor load- so I'm wondering what else I might be missing. -Don _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
