Build an "enterprise" backup box

[Conti93]

Hello, I'm Matt from Italy.
I work as a SysAdmin, and I'm seeking advice to build a backup NAS for our 2 Qnap.
At the moment we have a Qnap TS-470 with 4 3TB HD in RAID5 and a TVS-1271 with 8 3TB HD in RAID5 + 4 500GB Sammy 850 Pro as cache, for a grand total of almost 30TB.. To backup somewhere.
We have a 30/30 Mpbs fiber internet, so cloud backup is not viable. The easiest alternative is an "offsite" backup NAS to Rsync the two NAS. It will be placed in a dependance, so quietness is a must (or at least, I'll try..).
I was planning to get at least 12 WD Red 4TB HD (2 Raidz composed by 6-7 HD each, or 2 Raidz2 composed by 8 HD if the budget permitts..), a 16 (/20/24) bays rackmount case, supermicro board with a Xeon (don't know which for now), decent PSU and... 16? GB of ECC RAM. A handful of Noctua fans and a NH-U12 should keep the NAS cool & quiet.
Now: This machine will run (almost) only at night, syncing ONLY the data between the other 2 Qnap over gigabit eth; will 16GB of RAM be enough?
Also: I can't seem to find a used Supermicro 16/20/24 bays rackmount case in Italy, or even in Europe: The only ones that I can find are brand new Case Logic from servercase.uk or similar, but none of them seems to have 120mm fans (like the Norco with the proper aftermarket fan bracket..). Does someone know where to find a decent case in Europe?

TL; DR: Are 16GB of RAM enough for 30TB used for nightly 10-100Gb RSync? Where the heck can I find decent cases in Europe/Italy?

Thank you.
Mattia

 

[Robert Trevellyan]

Are 16GB of RAM enough for 30TB used for nightly 10-100Gb RSync?

Could be, you can try it and add more if necessary.

 

[Conti93]

After a bit of discussion on Reddit: https://www.reddit.com/r/freenas/comments/48o9v0/big_freenas_backup_box/

I've been brainstorming on the net all the evening, and I was trying a C612 build to overcome the 32GB RAM limit:
- MB Supermicro X10SRH-CLN4F 549,90€
- CPU Xeon E5-1620v3 314,71€
- RAM 2xSamsung 16GB compatible DDR4 Registered ECC DIMM 196,80€
- SASExpander Intel RES3FV288 SAS 290€ (Eek! That's the cheapest that supports 6Gbps SATA!)
- Case X-Case eXtra Value 424 350€
- PSU ?? non redundant 80 plus gold (maybe corsair CS..) about 100€
- HDD 16x4TB WD Red at least (6TB cost 5% more, but it might be viable..) about 2500€ from Amazon.it

I DO know that the LSI 3008 RAID controller embedded in the MB hasn't been tested for billion of hours like the LSI 2308 included in "older boards" and has been problematic to someone, but Supermicro doesn't make a C612 MB with a 2308 embedded, and since I'll use only 6Gbps SATA drives ATM it should work without a hitch.

The Intel SAS expander costs a metric whackton of money, but a rackmount case with an embedded SAS expander costs much more, so, since it should be completely transparent it should work great.

It's quite overkill, but the price isn't much different and I can add more than 32GB of RAM, and since in a far future I would like to add more drives, it should be worth it. Am I wrong?