Build a dual > 10 TB storage system

WDC says Black drives aren't suitable for RAID, now pushing people with small arrays to Red drives, and larger arrays to RE series drives.

This is a backup system? What does the primary data storage system look like?

RAID 5 with either large disks or a large number of disks (and 2TB x 5 approaches the fine line between this) you actually have a good chance of losing the entire array in the face of a lost drive. It will take somewhere around 6-12 hours to rebuild the array, depending on whose RAID implementation you use. During that time either another drive could die, or much more likely there is a sector read error or parity error (could be either lost sectors or corrupted data not caught by or incorrectly reconstructed by, drive's ECC).

You want NAS 4 Free or Nexentastor for the primary storage and have it build clones. To get corruption mitigation, it needs to happen upstream on primary data otherwise the benefit is significantly less if you're using resilient storage as a backup for potentially already corrupt data.

No I would not do this. You are talking about a large array that will take hours to days to rebuild should anything go wrong. And DAS increases the risk of problems. This storage should be NAS based. If you need more speed, pay for 10GigE. Or create a smaller RAID 0 with smaller but fast HDDs or an SSD and use those for fast local storage but keep most of the data on network storage.

If you want off-site you have to pay for it in one form or another. A duplicate NAS isn't that expensive and you can do the initial sync locally which will be much faster. And then locate the NAS elsewhere and sync with rsync.

 

Do you particularly want to build your own RAID NAS ? I would just buy 2 decent off-the peg units and populate them with 3TB drives.

 

Already done.
My Synology NAS is 10TB in RAID 5, which is backed up onto the expansion unit directly connected to it.
The most important data is also backed up to external disk.

 

No, no and no.

You shouldn't really rely on identical drives, that will significantly increase the likelihood of multiple failures within a short timespan. If you insist on using the same models (performance reasons, convenience, economy, etc.), at least make sure the individual drives are from different production batches.

 

I had this problem with some 1TB Samsung units. I solved it by getting drives from distributors in 3 different countries.

 

That's how Promise sell all there Pegasus stuff..You will get the same brand of drive but the batch serials are always different...I have Hitachi's in mine now, after one Seagate failed...I just asked them d=for a replacement drive, but they insisted on a full replacement...No issues since.

 

Good solution, but it will unfortunately decrease one's chances of getting nice deals, won't it?

Good to hear! Always nice when a company does things right for a change.

 

Not really. As it turned out the price was pretty much the same. I had thought of buying from Amazon in 3 different countries to avoid shipping costs, but the source is just from one set of stock, so I avoided this.