NAS Rebuild

Howdy everyone,

Over black friday I was able to pick up a pair of WD red 4tb drives, which is great. years ago I built a NAS (with the help of this community) and it has served me well ever since. However, I didn’t make the best choices at the time, going with a raidz2 setup with 4 drives instead of another number, limiting my space to half of the drives. My plan is to rebuild my array with the 6 disks instead, effectively doubling my usable space. I have a couple of questions though, as the home NAS game has probably changed more than I’ve kept up with in the last 5 years, and also need some advice on how to go about the data transfer, since I wont be able to preserve it when I rebuild my pool.

Server specs currently:
CPU - i3 whatever it is (the last gen that supported ecc, iirc)
Mobo - Supermicro X10SL7-F-O
RAM - 16gb crucial ECC
HDD - 4x 4tb HGSTS NAS
PSU - 360w seasonic gold
Case - Fractal Node 804
OS - FreeNAS

Used as general purpose backup, storage, and archive. I back up all my pictures from my phone onto the NAS, as well as keep any projects or backups on here. Data security is important because of this, I want to make sure every reasonable step is taken to make sure the data on here is safe. In terms of other storage, I keep my media collection (movies, tv, music, etc.), as well as a backup of each of my games on here (this saves a lot of time/bandwidth on my internet). Besides that, not much else on here.

Needs to serve primarily Windows based systems, with some linux as well. No concerns for MacOS, would be nice to have an easy way to connect to android devices as well.

Eventually, (whenever I get around to it) I’ll be swapping the i3 for a Xeon 1230v3 to allow this system to handle some transcode for a plex setup. So I guess that counts as a need?

I’ll be upgrading this system to 10gbe sometime in the spring.

So now my questions:
1 - Will there be any issues with mixing 7200rpm and 5400rpm drives, besides a lower performance? I don’t think so, but I wanted to be double check.

2 - Will my 16gb of RAM be enough, at least for the while? I know that you’re supposed to try and maintain a 1-1 ratio of gb of RAM to tb of HDD space with zfs, and this would throw my ratio out of whack. I’m typically the only user, at most we have 2-3 people using at a time, just watching movies off of the server. (no encode/decode, just watching the files stored on the server) I’d like to add in the additional 16gb later, but how much of a priority should this be?

3 - Is FreeNAS still the go to option, or are there other options that are better now? I’d like to keep zfs, but if there are better fs options now I’m open to change. I’ve been using FreeNAS for the last 5 years, so I’m comfortable with it, but again I’m open to change. I’ve seen a lot on zfs for linux, as well as unraid and maybe some others. Can someone more in the loop fill me in?

4 - Is it a good idea to continue to use zfs and raidz2 for my use, or would I be better served going to a mirrored vdev setup, or something else entirely? Again, open to change here, I just dont want to sacrifice too much of my redundancy or data security here.

Transferring my data
This is where I’m looking for advice or suggestions: how to safely move and store my data in the time that it takes for me to reconfigure the zpool for 6 drives. I wont be able to keep it on any of the drives I have now, since they’ll all be needed for the new pool, but I need someway to store and transfer it. We’re talking around 5tb of data here, and with my internet speeds and bandwidth caps uploading to cloud and downloading isnt an option, which leaves me with hardware. I’ve considered trying to grab a 8tb easystore and using that in the meantime to keep everything, then selling it on craigslist or whatever when I was finished, or maybe keeping it around. The problem I have with that plan is that if that one drive were to fail, I’d lose all my data. The obvious solution is just to buy 2, and have a redundant backup, but that seems a bit of a sledgehammer solution to an otherwise fairly simple problem. I’d love to hear if anyone has some ideas on how I can back my data up safely for the few hours/weekend this will take.

I’m adding 2 drives to my NAS. Because it’s zfs, Is freeNAS/zfs still the go to? Should I stick with zraid2 for 6 drives? How should I go about securing my data during the transfer if cloud storage is not an option?

Any help would be great! Feel free to ask any questions, I tried to be as comprehensive as I could.

Firstly, I think it would be wise to invest in some sort of backup solution for your NAS as it doesn’t sound like you currently have one and your data is very important to you. Do this ASAP regardless of what you decide to do next. Backup and even secondary backups are not a “sledgehammer” approach or should be considered optional, it is simply the prudent thing to do. Remember that parity is not backup.

A relatively inexpensive per GB and slower external USB drive or two (more the merrier) can do the job for the size of data you are talking about. With multiples, you can even cycle them out to keep offsite backups for added safety.

As for alternatives to freeNAS, check out the below GN video where Wendel visits and gets ZFS up and running on Unraid.



That ratio is for ZFS with deduplication enabled, so if you never enable dedup, then a lower ratio is fine in most cases. Just never enable dedup.

I don’t backup the majority of my online since the pricing and internet speed won’t work with the amount of data I have. I use external HDDs, since Raid(z) is not backup. So this is a good idea.

1 - no, you’ll have uneven performance and perhaps different fill rates, but it’s not going to break anything
2 - yes that’s enough for a home nas
3 - yes, freenas is still the winner for ease of use as a nas with zfs
4 - I prefer mirrors, it’s easiest to grow and performs better, only downside is the space cost, but the cost of disks is so low that it shouldn’t be a deal breaker these days

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Also think down the line, what you might like to do to set up the pool for the next upgrade; whether it is swapping for larger drives or adding extra vdevs, mirrors would make it easier.
You can make 3 (or more) deep mirrors if you wanted more options for redundancy, but that obviously takes more drives.

Doesn’t really help you transition your data, but perhaps if you got the new pair of drives in as a new, separate pool of one mirrored pair, you could transfer most of your data to the new pool, and only have to worry about 1TB left over?
Then the existing drives could be added too the new pool as two pairs of mirrors?
So ending up with 3 paired 4tb drives, approx 10tb useable, any one drive can fail with no loss, then the chance of a second drive failing causing data loss maybe lower?

Sorry for long post saying stuff you already know.
Oh and do you already use lots of datasets and snapshots? Because then you could zfs send/receive between pools for faster transfer?

@Klingon00 Yeah, I know not having a backup is bad. That’s actually something I already have a plan in motion for. I keep pictures, some of my music (recordings of my grandfather playing) and other things backed up offsite, but not all of the data. If I lose my steam games, I can always download again. Ideally after upgrading the server I’d like to use a cloud backup service for most stuff, music, etc., and still maintain the offsite backup as well for personal/important data.
Also, thanks for the link to the unraid vid, I hadn’t seen that one. Will check that out after work.

@TheCakeIsNaOH I thought the 1-1 was for the ARC/ZIL, not dedupe. It was my understanding that you typically wanted 4-5gb for each tb of data if you’re using dedupe. Are you sure that the 1-1 is for dedupe? In either case, I dont think it’ll be a huge performance impact given that I dont dedupe, and the demands for my NAS are fairly low.
I know that raidz is not a backup, see above. My concerns are less with using external drives to have a backup, and more with getting my data from the current pool to the new one.

@freqlabs Thanks for the quick/to the point responses, I’ll have to get more familiar with mirrors I suppose, as ease of growth is a big plus for me.

@Trooper_ish I hadn’t thought about that! That’s a great idea, using drives for another pool or mirror. In theory I could just grab 2 8tb drives, have the 2 copies of my data for rebuilding the pool, then come back after the fact and add one more drive and have another pool, or mirror, etc. I actually hadn’t considered adding another pool to this system at all and the idea of getting some drives for the small amount of time I need to recreate my current pool but then having another afterwards seems great. I’ll have to sit and think on this for a while as to what would be the best solution.

I have snapshots enabled, but I’m not sure what you mean with datasets. So I guess that means I dont use a lot of them! Related to this though, would I be able to set up a separate zpool, with a different number of disks and different raidz (raidz1) and transfer data using a snapshot? If that’s the case then I could potentially just grab another 3 4tb disks and setup a second zpool in raidz1 and transfer data to there, then add my 2 new disks to the old pool and transfer back. I cant believe I didn’t think of this ,this is a great idea, I just need to figure out what would be best.

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