slow disk performance

[Chavell3_84]

Hi community,

I have, won't say "a problem", but an issue(is that somewhat better? :P ) with my TrueNAS v12.
I'm running a Raid-5(Z1) with 3x 4TB disk but when I try a performance test, the throughput is constantly around 34MB/s...
I would at least expect somewhat around 100MB/s, well as my network with 1Gbit would be the next bottleneck
Another test on a single pool(only 1 SSD attached) also showed only 34MB/s.

I've tested it with SMB(on the 3x 4TB pool) and with NFS(on the SSD pool) but the performance is always the same.

I also attached some SLOG and LARC2 device cache, running on 2 different NVME devices, to get some more performance but it does not impact the performance at all...
An

Code:

pool: data
state: ONLINE
scan: resilvered 96K in 0 days 00:00:03 with 0 errors on Thu Dec  3 20:36:04 2020
config:

        NAME                                            STATE     READ WRITE CKSUM
        data                                            ONLINE       0     0     0
          raidz1-0                                      ONLINE       0     0     0
            gptid/0bfc1eac-b787-11ea-a9e3-dc9c5207e9e3  ONLINE       0     0     0
            gptid/0c0ceeaa-b787-11ea-a9e3-dc9c5207e9e3  ONLINE       0     0     0
            gptid/0c0374ea-b787-11ea-a9e3-dc9c5207e9e3  ONLINE       0     0     0
        logs
          mirror-8                                      ONLINE       0     0     0
            gptid/4fc3dae0-3598-11eb-b27d-18c04d05d4ca  ONLINE       0     0     0
            gptid/4fc9c207-3598-11eb-b27d-18c04d05d4ca  ONLINE       0     0     0
        cache
          gptid/4fc64836-3598-11eb-b27d-18c04d05d4ca    ONLINE       0     0     0
          gptid/4fcc3218-3598-11eb-b27d-18c04d05d4ca    ONLINE       0     0     0

SMB test:
Direct I/O

Bypass Write-Cache:

VM on SSD pool:

The system is running on a Intel Pentium G5500T with 16GB DDR4 RAM.
Also interesting, the read-performance is worse than the write performance...

Hopefully you have some ideas for me to investigate, what could be the issue...

Thanks

 

[outofnames]

I would check the network connection I had some problems with a bad network cable that was causing all kinds of bad speeds on read and write.
If not that then possibly the network card you are using?

 

[sretalla]

The first thing to do is to work out where the performance is getting stuck... "the bottleneck"

You should start by having a look at iperf3 (a bit of forum searching or google explains how to use it) to see if the problem is the network.

Then use fio on the TrueNAS host directly to check the performance of the pool directly (again, a bit of forum search or google should find you some fio commands to try).

With only 16GB of RAM, I would be removing L2ARC as that's likely to be making things worse at this point. Also you haven't shown a need for SLOG (although it may help with write speeds on NFS, depending on how you're connecting), so take that out too (for now).