Abysmal write speeds

[DerInternets]

Cheers everyone,

 

I am currently in the process of setting up a new homeserver as my Synology 218j did just not have the storage space and power that i needed.

Current Hardware:

Asrock J4105 mini-itx board

8 GB Ram

4x 8TB WD Red as the array, connected to the onboard-sata controllers (one is the processors intel one, the other one's a on-board ASMedia ASM1061).

2x 1TB 2,5" 5400 Disks that i'd like to use as either cache or unassigned disks for my dockers, vms and such as they don't consume a lot of power and are a lot less noisy that the big reds. Those are running of of a cheap chinese marvell 88SE9125 pci-e sata-controller.

 

Network connection is established via the onboard controller (Gbit lan) plus another usb gbit lan adapter (for shit's and giggles, i don't expect the system to saturate 2 gbit-ports and i don't need it to).

 

Currently, the 2 2,5" disks configured as a cache pool, balance is set to raid 0 (for max. speed, more on that in a sec.). The WD Reds are more or less empty, parity has been calculated (after the 3rd try - thx to badly shielded sata cables).

 

So far, setting up the system was great, everything was easy to understand, (almost) no fiddling around with config files and such. But:

My write speeds are hopeless. I am aware that this is unraid's great weakness, but I am getting between 5 and 15 Megabytes/sec out of the damn thing.

 

Here's what i've tried/checked already:

- Activated "turbo-writes" aka reconstruct write - no change in speeds

- Activated and deactivated caching (cache yes, cache no, disabling the cache disks completely) for the share i am writing to (currently that's the appdata share) - no change in speeds

- switched cache pool from auto to raid 0 (more out of desparation, because i really don't want my cache to be susceptible for data loss) to no avail.

- I've checked hdparm and all disks have write-caching enabled.

- Unplugged the 2nd LAN-adapter - nothing.

 

I've tested transfer speeds by writing to an smb share from a windows machine, also connected via Gbit-LAN.

 

Any tips?

I'd really like to use UNRAID instead of OMV or ubuntu (tested both, not as nice as unraid), but transferring my 5 TB of data to the array at those speeds would take me 2 whole Weeks. Not gonna happen - Help!

 

Edited July 19, 2020 by DerInternets

[itimpi]

It might be worth posting your system’s diagnostics zip file (obtained via Tools -> Diagnostics) attached to your next post to see if we can spot anything that springs out.

[DerInternets]

I knew I forgot something

 

 

node-diagnostics-20200719-2036.zip

[DerInternets]

For whatever reason my Server just descided that it is able to do things more quickly - after several hours of one to two-digit transfer speeds it now delivers roughly a 100 Megabytes / sec when writing directly to the array.

 

I have no idea what the problem was but it seems that it solved itself. I will now revert back to raid 1 for the cache drives, restart and then transfer all my media to the array. Fingers crossed the first 2 TB will be transferred by midnight.

[trurl]

54 minutes ago, DerInternets said:

will now revert back to raid 1 for the cache drives, restart and then transfer all my media to the array. Fingers crossed the first 2 TB will be transferred by midnight.

Don't cache the initial data load.