@relling
"For small, random read IOPS the performance of a single, top-level
vdev is
performance = performance of a disk * (N / (N - P))
133 * 12/(12-1)=
133 * 12/11
where,
N = number of disks in the vdev
P = number of parity devices in the vdev"
performance of a disk => Is this a rough estimate of the disk's IOP?
"For example, using 5 disks @ 100 IOPS we get something like:
2-disk mirror: 200 IOPS
4+1 raidz: 125 IOPS
3+2 raidz2: 167 IOPS
2+3 raidz3: 250 IOPS"
So if the rated iops on our disks is @133 iops
133 * 12/(12-1) = 145
11+1 raidz: 145 IOPS?????
If that's the rate for a 11+1 raidz vdev, then why is iostat showing
about 700 combined IOPS (reads/writes) per disk?
r/s w/s Mr/s Mw/s wait actv wsvc_t asvc_t %w %b device
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 c0t0d0
1402.2 7805.3 2.7 36.2 0.2 54.9 0.0 6.0 0 940 c1
10.8 1.0 0.1 0.0 0.0 0.1 0.0 7.0 0 7 c1t0d0
117.1 640.7 0.2 1.8 0.0 4.5 0.0 5.9 1 76 c1t1d0
116.9 638.2 0.2 1.7 0.0 4.6 0.0 6.1 1 78 c1t2d0
116.4 639.1 0.2 1.8 0.0 4.6 0.0 6.0 1 78 c1t3d0
116.6 638.1 0.2 1.7 0.0 4.6 0.0 6.1 1 77 c1t4d0
113.2 638.0 0.2 1.8 0.0 4.6 0.0 6.1 1 77 c1t5d0
116.6 635.3 0.2 1.7 0.0 4.5 0.0 6.0 1 76 c1t6d0
116.2 637.8 0.2 1.8 0.0 4.7 0.0 6.2 1 79 c1t7d0
115.3 636.7 0.2 1.8 0.0 4.4 0.0 5.8 1 77 c1t8d0
115.4 637.8 0.2 1.8 0.0 4.5 0.0 5.9 1 77 c1t9d0
114.8 635.0 0.2 1.8 0.0 4.3 0.0 5.7 1 76 c1t10d0
114.9 639.9 0.2 1.8 0.0 4.7 0.0 6.2 1 78 c1t11d0
115.1 638.7 0.2 1.8 0.0 4.4 0.0 5.9 1 77 c1t12d0
1.6 140.0 0.0 15.1 0.0 0.6 0.0 4.4 0 8 c1t13d0
1.3 9.1 0.0 0.1 0.0 0.0 0.0 1.0 0 0 c1t14d0
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