New to FreeNAS/ZFS, looking for a sanity check.

[stevecyb]

I am a home user, and I've got probably a TiB of stuff on different systems (some Linux, some Windows) I want to consolidate, so I decided to go all-out and ordered an FreeNAS Mini XL +. (I even asked for a second SATA DOM.) So I shouldn't have any issue with hardware. I then bought 8 WD Red 4TB drives.

(With 32TB to store 1TB, it would seem that: Yes, I am trying to become the first person who says "I have too much storage.")

I am extremely bandwidth-limited as far as the internet goes (it's a cellular hotspot with a monthly limit quite a bit less than a TiB).

I was originally thinking of doing off-site back ups over the USB 3.0 port to a 4TB portable drive, but looking around this is highly discouraged for reasons that seem to be more than just purist "your backup isn't quite safe" considerations.

So now I'm thinking: First, I'll create a single vdev pool, RAIDZ2 with either 4, 5, or 6 drives (should give me 8, 12, or 16 TB or so, respectively). I'll enable snapshots, etc.

I'll then set up another single vdev pool, a mirror of two drives. For backups, I will simply arrange to copy things to this pool from the other one. "But wait, that's not an offsite backup!"

Well maybe it can be...I can't quite figure this out.

My thought was that to make an offsite backup, I'd "break" the mirroring, physically remove one of the two drives in the vdev, and take it offsite. I'd take a third drive, put it into the NAS, and re-create the mirror with that drive. When I want to do another offsite backup, I "break" the mirroring again, this time taking the drive that has been in the NAS the longest, and replace it with a drive I had offsite. This way, I can have three (preferably 4: two in the NAS, one offsite, one being transported to/from offsite) drives and I rotate them.

So questions:

1) Is it still a royal pain in the hindquarters to manipulate mirrors like this, or is it now finally doable in the GUI?

2) Is it still even more of a royal pain--call it an imperial pain in the hindquarters--to do this with encryption? I found a thread about this with instructions I simply couldn't make heads or tails of. (Encryption, of course, would be useful for an offsite disk. But if I can't encrypt the drive, perhaps I could encrypt what I put on the drive as a second-best solution.)

3) Most crucially: Would the drive that's offsite be, by itself, readable on (say) a Linux box that has had ZFS installed on it, or would "both" drives of the mirror be needed for it to function? (As I painfully discovered is the case with Windows "dynamic disks"?) If the answer is that I'd need both drives, then this strategy can't work.

PS...I try to add tags, make a typo, and end up getting sent to a page that forces me to wait for 10 seconds, reaccept the terms, and loses the last tag I added. So I give up adding more tags.

 

[dlavigne]

That does sound like an unreliable solution...

 

[stevecyb]

That does sound like an unreliable solution...

Yeah, I ultimately realized breaking a mirror was...a bad idea. I posted a different thread with an idea much closer to where I'm at now, and THAT got modified a lot in response to people's advice: https://www.ixsystems.com/community/threads/mounting-ntfs-to-copy-to-the-disk.79746/

My system was originally intended to have 8 4TB drives, 5 of them in RAIDZ2, one hot spare, and two for the backup mirror.

Instead of the mirror, I'll simply create two (or maybe even three) one-disk pools, and back up to them both (most likely using copies=2). I'll then pull one (call it bak1) and take it offsite. When I want to take another one (call it bak2) offsite, I bring back bak1, install it in the NAS, and make a fresh backup to both bak1 and bak2; then I take bak2 offsite.

This will start to fall apart when I find myself with more data than can fit into one disk. I'm not there yet, give it a week or two :)

Meanwhile, since I had two dead drives to start with, I'm exchanging those for 6TB drives (an absolute steal right now at one certain retailer). Those larger drives will be my backup drives. So right now I have 5 in RAIDZ2, 1 as backup (no offsite). When the two replacement drives arrive, they become backup drives, and I may just make that extra 4TB into a hot spare. (This at least staves off backup-schema-breakdown until I have 3TB of data...or six if I'm willing to go with copies=1.)

That does leave me with a possible situation where a catastrophe happens while both of my backups are momentarily on site, so that's why I'm starting to think: THREE backups, one always offsite, one always onsite, the other would be in the NAS or moving from one site to the other: starting with bak1 and bak2 in the machine, pull bak1, take it to offsite, retrieve bak3 from offsite, put it in NAS, update it. Next time take bak2 to offsite and bring back bak1. So I should perhaps increase my order to THREE of those 6TB drives...that'd be a total of 9 drives, but that's OK; as only 8 will ever be in the NAS. Hmmm, I'd need to get another drive tray, too. Hopefully IxSystems will sell me one.