Questions about new build and pools

[ploplop]

Hello everyone,
Bit of a noob here, Iva built two small FreeNas storage systems in the past using old workstations and I'm always amazed at how stable they were, even after years and without much hassle. Now I'm thinking of making a build for a TrueNas Scale NAS for my family to use as a plex media server only. I was about to purchase everything when I decided that it would probably be best to check if I'm not making any mistakes. The link for the Build is here (build on pcpartpicker) and is going to be made of 4 drives (4Tb each) as RAIDZ-1 to create a pool that will then be split into a couple of datasets, and in a few months buy another 4 drives that will also be setup as RAIDZ-1 and add them to the same pool.

My question is, is it better to wait a while and just purchase 8 drives that will be set as RAIDZ-2 or does not it not matter in this config ? Also will I be able to expand the existing pool with the newly purchased drives (if I go the 4 drives route) or will I have to create another pool.

More Details:

1. This NAS will not have any important data on it, just the media for plex (which is already backed up in a bunch of different, separate drives), I don't care if I loose all of it, tough I'm trying to do things right to avoid the hassle in case it does happen.
2. The reason I'm going with TrueNas scale is to have the GPU passthrough for plex to handle transcoding, since we might be 5 or 6 people streaming at the same time in different resolutions (1080p to 4k), this is a worst case scenario, most of the time I think it will 2 or 3 people at the same time, but I'd still like to offload that to the GPU.
3. The CPU, RAM, GPU and fans are from an old computer I have, that's why I'm using them.

If I might wrong about any of these assumptions, or need to provide more info or anything else, please feel free to tell me, I've looked through the documentation and tried to get as much info on all of this as I could before posting, I fairly confidant I can do this, but I just wanted to make sure before purchasing everything.

Cheers

 

[sretalla]

My question is, is it better to wait a while and just purchase 8 drives that will be set as RAIDZ-2 or does not it not matter in this config ?

I don't care if I loose all of it,

See the charts (red is pool loss) of double disk failure... the only real difference would be likelihood of pool loss. Performance probably won't differ enough to notice. You may want to consider future additional VDEVs... probably should be 8-wide RAIDZ2 if your first VDEV is one of those, so harder to expand later.

Also will I be able to expand the existing pool with the newly purchased drives (if I go the 4 drives route) or will I have to create another pool.

Yes, you can always add another VDEV to an existing pool, that's fine.

 

[ploplop]

Hey @sretalla , thanks for your reply, that's exactly what I wanted to know. I think I'll follow your advice and wait a little while to get the 8 drives setup as RAIDZ2, which should give me 24Tb of usable space, more than enough for my needs for the next few years !
I don't think I'll be needing more space in the future but if I do, it'll probably be added to another pool, so I don't mind. Also this build won't be able to handle more than 8 drives, I could still add 4 drives connected via sata but that would require a new case.

Thanks again !