fdisk -l Disk /dev/sdb: 14.55 TiB, 16000900661248 bytes, 31251759104 sectors Disk model: ST16000NM001G-2K Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Device Start End Sectors Size Type /dev/sdb1 128 4194304 4194177 2G Linux swap /dev/sdb2 4194432 31251759070 31247564639 14.6T Solaris /usr & Apple ZFS Disk /dev/sdc: 14.55 TiB, 16000900661248 bytes, 31251759104 sectors Disk model: WDC WUH721816AL Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Device Start End Sectors Size Type /dev/sdc1 128 4194304 4194177 2G Linux swap /dev/sdc2 4194432 31251759070 31247564639 14.6T Solaris /usr & Apple ZFS Disk /dev/sda: 14.55 TiB, 16000900661248 bytes, 31251759104 sectors Disk model: TOSHIBA MG08ACA1 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Device Start End Sectors Size Type /dev/sda1 128 4194304 4194177 2G Linux swap /dev/sda2 4194432 31251759070 31247564639 14.6T Solaris /usr & Apple ZFS hdparm -tT /dev/sda hdparm -tT /dev/sdb hdparm -tT /dev/sdc hdparm -tT /dev/sdc hdparm -tT /dev/sdb hdparm -tT /dev/sda /dev/sda: Timing cached reads: 51598 MB in 2.00 seconds = 25848.22 MB/sec Timing buffered disk reads: 748 MB in 3.01 seconds = 248.86 MB/sec /dev/sda: Timing cached reads: 52576 MB in 2.00 seconds = 26340.46 MB/sec Timing buffered disk reads: 746 MB in 3.00 seconds = 248.57 MB/sec /dev/sdb: Timing cached reads: 55360 MB in 2.00 seconds = 27735.71 MB/sec Timing buffered disk reads: 762 MB in 3.00 seconds = 253.69 MB/sec /dev/sdb: Timing cached reads: 53760 MB in 2.00 seconds = 26935.18 MB/sec Timing buffered disk reads: 760 MB in 3.00 seconds = 253.11 MB/sec /dev/sdc: Timing cached reads: 55920 MB in 2.00 seconds = 28018.67 MB/sec Timing buffered disk reads: 688 MB in 3.01 seconds = 228.89 MB/sec /dev/sdc: Timing cached reads: 56500 MB in 2.00 seconds = 28307.56 MB/sec Timing buffered disk reads: 694 MB in 3.01 seconds = 230.94 MB/sec dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=1M count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/WD/tmp.file bs=1M count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=1M count=1000 oflag=dsync truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 27.3523 s, 38.3 MB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 27.5908 s, 38.0 MB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 27.5954 s, 38.0 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 27.3672 s, 38.3 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 26.2732 s, 39.9 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 28.0959 s, 37.3 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 59.0902 s, 17.7 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 59.1742 s, 17.7 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=1M count=1000 oflag=dsync 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB, 1000 MiB) copied, 56.4228 s, 18.6 MB/s dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096k count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096k count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096k count=1000 oflag=dsync truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 68.3543 s, 61.4 MB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 81.2077 s, 51.6 MB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 65.7458 s, 63.8 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 73.5321 s, 57.0 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 82.2295 s, 51.0 MB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 64.3074 s, 65.2 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 84.6373 s, 49.6 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 106.494 s, 39.4 MB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096k count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4194304000 bytes (4.2 GB, 3.9 GiB) copied, 92.5211 s, 45.3 MB/s dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096 count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096 count=1000 oflag=dsync dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096 count=1000 oflag=dsync truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 8.73942 s, 469 kB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 9.23189 s, 444 kB/s truenas# dd if=/dev/urandom of=/mnt/SEAGATE/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 8.75026 s, 468 kB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 10.4897 s, 390 kB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 9.94617 s, 412 kB/s truenas# dd if=/dev/urandom of=/mnt/WD/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 7.15292 s, 573 kB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 38.0139 s, 108 kB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 37.4474 s, 109 kB/s truenas# dd if=/dev/urandom of=/mnt/TOSHIBA/tmp.file bs=4096 count=1000 oflag=dsync 1000+0 records in 1000+0 records out 4096000 bytes (4.1 MB, 3.9 MiB) copied, 37.8507 s, 108 kB/s