Noob Storage Question

[MrAnderson]

Howdy ya'll,

Now I know this question has been asked many many many times but I don't know if the answers I found relate to me or I'm not sure how to relate it to me, what i want to do is fairly simple and nothing too crazy(i hope).

I'm working on building a freeNas 11 Server ; And what I'm trying to accomplish is having a storage system that'll back up my files across multiple HDD so i have a long term backup storage system and to be able to access the files using nextcloud. I'm comfortable with the build of my system the hardware I need but i'm not sure on storage I bought 4 x 2TB because that's how much the budget allowed for, however i see for Raidz2 it's best to have 6 - 8 HDD. (I know raidz2 is not my only option)

I guess my question is can i accomplish what i need to accomplish with 4 x 2TB HDD for now and expand later : (Storage backup with redundancy)

I'll take any articles you can provide or any advice.

Should I use raidz2 if i only have 4 x 2TB : I know if i use raidz2 if one drives fails everything is okay but that drive should be replaced - if two drives fail i lose everything inside of the pool is there a better option to use ?

 

[hervon]

With raidz2 4 x 2 tb you only get approx 4 tb of storage. If that’s enough for you then go for it! Add another drive and you ll get approx 6 tb of storage . More efficient. There is no easy way to expend raidz2. Good planning before is important!

 

[danb35]

There is no easy way to expend raidz2.

...which is a big part of why this guy recommends mirrors rather than RAIDZn for home use--expanding the pool is just a matter of adding another pair of disks. I don't agree with him as an absolute rule, but he makes some good points.

 

[MrAnderson]

Thank you for your response : 4tb is alright for now.
And if i'm not mistaken if i did want to add another drive - I'll have to add another set of drives (2+ HDD) and create a another Vdev to add to the pool and it can be any raid i need it to be correct ? 4ex. use Mirror instead.

 

[MrAnderson]

...which is a big part of why this guy recommends mirrors rather than RAIDZn for home use--expanding the pool is just a matter of adding another pair of disks. I don't agree with him as an absolute rule, but he makes some good points.

Thank you I read that article - I do think Mirror is the best way to go if i want to expand - I just want to make sure I have the best system for redundancy.

 

[blueether]

If your hardware can support 8 drives (plus the boot pool) I think I would go with Raidz2 of 4 x 2TB giving 4TB storage now and can loose any two disks and still have a viable pool. I think that this gives better redundancy for the same storage as 2 mirror vdevs in the pool.

Then when you can afford another 4 disks extend the raidz2 pool with another raidz2 vdev.

@danb35 what would you think of that as an option?

 

[danb35]

what would you think of that as an option?

Kind of a toss-up for me. Yes, redundancy is better compared to striped mirrors. OTOH, performance is worse, resilvers will take longer (though I don't place nearly the importance on that that the blog post I cited does), and expansion will be tougher.

 

[MrAnderson]

If your hardware can support 8 drives (plus the boot pool) I think I would go with Raidz2 of 4 x 2TB giving 4TB storage now and can loose any two disks and still have a viable pool. I think that this gives better redundancy for the same storage as 2 mirror vdevs in the pool.

My hardware only supports 6 drives and for boot i'll be using a mirror 16GB flash drive - Eventually i'm going to move from the 2TB drives. I just need a basic system right now that'll allow me to back up my data and expand in the future.

Mirror is better(or easier) for expansion if i'm not mistaken i can just add two more drives and add another vdev
Raidz2 I'd have to buy 4 more drives which my hardware doesn't allow because it can only hold 6 drives.