Adding additional storage

[NickF]

Hello Freenas,
I am actually a long time reader of these forums since 2013, when I built my first freenas machine, but I have never found a reason to need to post :)



First off let me state:
In October moved from my old server which was running a Core2Duo q6600 and 8GB of non-ECC memory (and did so since 2013 with 2x3TB WD RED hard drives mirrored)

My new server's specs are as follows:
i7-2600 (which I got for free), an Intel BOXP67BGB3 motherboard (cheap on ebay new in box) and 32GB Crucial DDR3 1600 memory (for super cheap), Intel X520 DA1, and currently 4 HGST 7k3000 2TB hard drives in a raid Z2.

I do not have ECC ram and I am aware of the possibility I may lose my array at any moment. The main purpose of my FreeNAS box is a Plex server, and I have 2 other copies of my data (one on a 6TB Mybook USB drive and more recently I put in my old server at a friends place with a 6TB HGST NAS drive.

The backups to the Mybook are manual and about every couple weeks.I dont do rsync/btsync/syncthing because if my non-ecc memory went haywire, would copy bad data. I also don't want it running all the time, becayse Then the Mybook is BTsync'd to my old server. It works for my purposes for now, weird things would have to happen for me to lose all 3 copies of my data at the same time.


I am now at the point where I am out of space, and I also wanted to take the opportunity to speed my pool up a smidge for the lulz because I recently upgraded to 10Gig. I picked up another pair of refurb HGST 2TB 7k3000's for $50 bucks each, and the plan was to destroy my current zpool and start over with a 6 drive raid Z2. I know that 4, 6, 8 ect are optimal configs for raid z2, but I was wondering if there are any other alternative configurations using 6 disks that will also increase my storage and maintain a 2 disk redundancy? I've heard of others striping vdevs, ect, and I am just wondering what the preferred config will be?
Whatever I end up doing, as drives die, I will be replacing them with HGST 4TB NAS drives, so that I eventually double my storage.

 

[Robert Trevellyan]

Striped mirrors (3 pairs of 2 drives) would increase IOPS but not streaming performance. You would be able to lose up to 3 drives without losing data, but only 1 from each pair. Since you say your box is primarily a Plex server, I see no point in picking striped mirrors. Stick with your plan for a 6-drive RAIDZ2 configuration.

 

[NickF]

Thank you Robert.
Striping data across 3 pairs of 2 drives, would that result in more, less, or the same storage space?

 

[Mr_N]

More than you have now, less than a 6 drive Z2 :)

 

[Robert Trevellyan]

Right, striped mirrors use 50% of your raw capacity for redundancy, whereas RAIDZ2 uses the equivalent of 2 drives of raw capacity for redundancy.