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My "budget" NAS can trivially saturate 10 GbE with a pair of Samsung SSD 980 PRO 2TB. It cannot saturate my 100 GbE connection. While it's true that TrueNAS p
by FullyFunctional 4y ago
My "budget" NAS can trivially saturate 10 GbE with a pair of Samsung SSD 980 PRO 2TB. It cannot saturate my 100 GbE connection. While it's true that TrueNAS perhaps can't quite get the same performance that you could get from XFS on the same hardware, that's really irrelevant for me as the features (snapshots and send) and data integrity is far more important.
- mgerdts 4y ago10 Gb/s =~ 1.2 GB/s Each 980 Pro can do sequential reads at 7 GB/s. ZFS with record size 128 KiB will do IOs at a size that will perform about as well as sequential regardless of the actual pattern. AFAICT ZFS has no need to push your drives beyond 10% of their overall capability assuming the clients are performing sequential reads or the reads are at least 128k. A more stressful read test would be a 4k random read where the working set doesn’t fit in the ARC. This would trigger a lot of read inflation. The write side is a bit more complicated as the drives may be able to write at over 5 GB/s if they have 30+% of their NAND erased, else the write rate will be closer to 1.4 GB/s. With a mirror this is pretty close to the network bandwidth. With some reads mixed in for COW the drive could become a bottleneck before the network or ZFS.
- FullyFunctional 4y agoI think we agree so I'm not sure what you meant. My point was that you could have made the stated "budget" all-SSD much much cheaper than what he did. A pair of 980 Pro would easily beat it on bandwidth. How close it would get on IOPS I don't know, but if you stay away for 128 KiB record size you should be in the neighborhood.