Truenas scale ssd plus hdd configuration

[Victor87]

Hello all

I will start with info that I'm a beginner with truenas platform and I trying all my best to understand this ecosystem. :)

I will build my first server from an old HP Z220cmt with i7 quad core processor, 16gb ram(for beginning), nvidia quadro k2000.

For a moment I have available one ssd 125gb for OS, one ssd 1tb WD red (for nas dedicated), one 4tb hdd WD gold and one more 2tb seagate hdd.
I know that is better to use same models and same capacity hdd, but on this moment this what I have .

My question is how can I create the pools to have best performance.
Server will be used for Plex streaming most of the time and to backup data like personal photos and video's.

I was thinking to create one single pool vdev from ssd (1tb) plus 2tb hdd for plex movies and the 4 TB hdd another vdev personal data. I know that will be no backup in case of one hdd fail but in the future will come more hdd and maybe I will have enough space for backups.

Thanks for helping and please don't throw with something on me because I'm a completely beginner :D

 

[Arwen]

I suggest reading up on ZFS. You mention using the 4TB HDD in another vDev for personal data. ZFS does not quite work like that. ZFS pools are made up of vDevs, and you can't, (generally speaking), select which vDev data is written to. So, your goal seems to be 2 ZFS pools, one made up of 1TB SSD & 2TB HDD, then a second pool using the 4TB HDD.

With that configuration of 1TB, 2TB & 4TB disks, you can't really make any redundancy in any pools. Most of us TrueNAS users want our NAS to survive disk loss, and also tend to be conservative in our disk configuration. (And in other hardware.)

Without any redundancy, any active disk block failure will result in data loss. And complete disk loss will result in total pool failure and all it's data. Now if you have backups, and accept that you may / will have to do restores on on failures, okay.


As for what would be the best performance, with that limited hardware, their really are not many choices. Plex streaming datasets should probably use larger block sizes, but other than that, I don't have any suggestions on configuration.

 

[Victor87]

Thank you for your answer.
Sorry I was writing wrong about vdev but you corrected me :)
That's the idea at this moment. Maybe I will order 2 more ssd Crucial mx500 2tb soon.
About losing data is not a big deal. My personal pictures and videos are saved to other external drives. I wanted only for next cloud to have everything online. So if one hdd fails is not so bad
Do you believe that if upgrade the ram to 32 GB will be a big difference for the future?

Thanks again for your help

 

[Arwen]

The ZFS feature ARC, (Adaptive Replacement Cache), does work better with more RAM. However, if you are not re-reading the same data, then upgrading RAM from 16GB to 32GB is less helpful.

Their are tools in both ZFS & TrueNAS to see how useful the ARC is. This can help determine if adding more RAM would improve performance. So, starting with 16GB and using it for a few months is perfectly reasonable.

 

[Victor87]

I will do like this then. Server will be ussed for downloading and uploading movies for plex. From my test until now everything works great. I order yesterday one more ssd and then I will do final configuration with new stuff.

I will keep reading about how it works more exactly vdev and zfs because I don't understand all. Before my server was with OMV but the truenas looks more better and with app store is perfect for me. On open media vault I get problems when the hdd was in spin down (hdd is not recognize by the software and everything was gone). From my test until now on truenas, a little bit disappointing is that I can't see the temperature of hdd when we don't use always on hdd option. Also spin down does not work if we don't disable smart function. Is a little bit tricky because I want to have smart, temp and also spin down hdd