I have O3X ZFS on a external HDD connected via USB3.0 and it runs fine, except that the internal HFS+ SSD gets extremly slow while ZFS is doing a scrub on the USB disk. As well as the systems seems to come to a complete I/O halt sometimes, but recovers after some time.
The slowdown during scrub I can verify easily, so I thought I show you my results:
1. I start a scrub on the external ZFS disk (disk3, ZFS ) scrub performs about 100MB/s
2. I start a duplication of file ( you see 20MB/s) on the internal SSD (disk0 , HFS+)
3. I stop zfs scrub as you see
3. Performance on HFS+ is back to normal ( >350MB/s)
- Code: Select all
disk0 disk3 cpu load average
KB/t tps MB/s KB/t tps MB/s us sy id 1m 5m 15m
48.59 251 11.91 123.35 300 36.14 5 5 91 0.98 1.13 1.23
21.33 6 0.12 0.00 0 0.00 2 1 97 0.98 1.13 1.23
0.00 0 0.00 0.00 0 0.00 2 1 97 0.98 1.13 1.23
0.00 0 0.00 0.00 0 0.00 2 1 97 0.98 1.13 1.23
40.00 2 0.08 0.00 0 0.00 2 1 97 0.98 1.13 1.23
4.00 1 0.00 0.00 0 0.00 3 2 95 0.98 1.12 1.23
0.00 0 0.00 0.00 0 0.00 4 2 94 0.98 1.12 1.23
0.00 0 0.00 0.00 0 0.00 2 1 98 0.98 1.12 1.23
14.75 78 1.12 11.87 56 0.65 3 2 96 0.98 1.12 1.23 scrub starts here
0.00 0 0.00 4.90 103 0.49 2 1 96 0.98 1.12 1.23
8.00 2 0.02 7.98 127 0.99 3 2 95 0.90 1.11 1.22
0.00 0 0.00 3.69 146 0.53 5 2 93 0.90 1.11 1.22
28.00 2 0.05 5.84 128 0.73 4 2 94 0.90 1.11 1.22
0.00 0 0.00 3.93 127 0.49 2 2 96 0.90 1.11 1.22
104.63 83 8.48 5.03 117 0.57 9 2 89 0.90 1.11 1.22
56.00 1 0.05 6.15 132 0.79 4 2 94 0.91 1.10 1.22
0.00 0 0.00 8.16 168 1.34 1 1 97 0.91 1.10 1.22
0.00 0 0.00 127.69 795 99.18 1 4 95 0.91 1.10 1.22 scrub now at speed
0.00 0 0.00 128.00 881 110.08 3 5 92 0.91 1.10 1.22
0.00 0 0.00 128.00 794 99.30 1 4 95 0.91 1.10 1.22
disk0 disk3 cpu load average
KB/t tps MB/s KB/t tps MB/s us sy id 1m 5m 15m
0.00 0 0.00 126.76 765 94.67 2 4 94 0.92 1.10 1.22
7.12 32 0.22 127.12 833 103.43 5 6 89 0.92 1.10 1.22
33.33 12 0.39 119.68 765 89.47 5 5 90 0.92 1.10 1.22
19.75 718 13.85 127.14 854 106.00 3 7 91 0.92 1.10 1.22 hfs copy starts here
116.35 214 24.33 126.99 849 105.35 2 5 93 0.92 1.10 1.22
54.23 425 22.48 127.07 789 97.92 3 6 90 0.93 1.10 1.22
118.90 196 22.73 126.94 800 99.15 4 6 90 0.93 1.10 1.22
118.91 189 21.98 126.98 835 103.54 3 6 91 0.93 1.10 1.22
124.34 486 58.97 120.08 657 77.03 3 5 92 0.93 1.10 1.22
125.96 183 22.54 127.13 846 104.98 3 5 92 0.93 1.10 1.22
121.54 185 21.95 127.00 861 106.74 7 6 86 1.09 1.13 1.23
125.22 182 22.28 127.07 788 97.74 4 6 89 1.09 1.13 1.23
124.49 178 21.59 126.91 785 97.32 3 5 92 1.09 1.13 1.23
124.44 179 21.78 126.98 837 103.73 2 5 93 1.09 1.13 1.23
121.13 407 48.14 120.08 705 82.73 3 5 91 1.09 1.13 1.23
124.02 205 24.87 126.60 787 97.25 2 5 93 1.08 1.13 1.23
77.99 2606 198.48 10.24 184 1.84 2 7 91 1.08 1.13 1.23 scrub stops
124.00 3001 363.38 0.00 0 0.00 2 8 91 1.08 1.13 1.23
125.17 2937 359.08 0.00 0 0.00 2 7 91 1.08 1.13 1.23
125.44 2798 342.82 0.00 0 0.00 4 8 89 1.08 1.13 1.23
disk0 disk3 cpu load average
KB/t tps MB/s KB/t tps MB/s us sy id 1m 5m 15m
125.33 2811 344.01 0.00 0 0.00 3 8 90 1.08 1.13 1.23
124.88 2701 329.40 0.00 0 0.00 3 8 90 1.08 1.13 1.23
123.09 2718 326.72 4.08 51 0.20 6 7 87 1.08 1.13 1.23 5 second zfs sync ?
124.33 2927 355.45 0.00 0 0.00 2 7 90 1.08 1.13 1.23
124.73 2499 304.43 0.00 0 0.00 2 7 91 1.08 1.13 1.23
124.59 1846 224.59 0.00 0 0.00 3 6 91 1.15 1.14 1.23
128.00 2844 355.53 0.00 0 0.00 4 10 86 1.15 1.14 1.23
127.80 3911 488.07 0.00 0 0.00 2 12 86 1.15 1.14 1.23
128.00 1368 170.95 0.00 0 0.00 3 7 90 1.15 1.14 1.23 copy stops
0.00 0 0.00 0.00 0 0.00 2 1 97 1.15 1.14 1.23
0.00 0 0.00 0.00 0 0.00 4 2 95 1.22 1.15 1.23
0.00 0 0.00 0.00 0 0.00 5 1 94 1.22 1.15 1.23
Patrick
Btw. for those in need of a ZFS backup script, ZFS-TimeMachine works fine with Zevo, O3X and FreeBSDhttps://github.com/jollyjinx/ZFS-TimeMachine