Another newbie with two Thunderbay 4

You have a good handle on this. Backups, plus an offsite plan is a great idea. the reason Certify is important is a new disk can have bad sectors anywhere on the surface. It may take months to encounter them, and you never knew you had a defective disk. Certify means at least you are starting off with reliable disks. (It also tests your total system, as if your overall system cannot read/write data reliably, you want to know that)

You will get slightly better performance if each Thunderbay is on it's own Thunderbolt bus.

SoftRAID can work well with USB, but RAID 4/5 is not recommended, as USB has too many issues with OS X. We have also found many multi-disk USB enclosures to add to this by not being reliable with heavy loads. This is especially true with "hardware RAID" capable enclosures used with SoftRAID in JBOD mode. (So while we support USB, it is not recommended.) If you want to mirror those drives, etc, that can work great.

Thanks. The USB thing may be moot anyway, I think one of the USB enclosures is faulty, perhaps it contributed to the HDD failures. I'll be throwing it out after I've retrieved the data.

So Raid 5 on each thunderbay, with a spare certified drive, and Crashplan will be fine? Going Raid 1+0 would be excessive if I'm going for Crashplan (I'm getting a family plan so that my windows machine and my wife's laptop will also be backed up).

RAID 1+0 is somewhat slower than RAID 5, but offers additional redundancy. RAID 5 should prove fine.

Good luck!

The 4TB drives in my first USB3 enclosure are dropping like flies! The third one (out of 5) has forced me to buy Disk Drill which is taking ages to recover, hopefully some files can be resurrected.

Is this more likely to be due to the enclosure or just that I bought these drives on the same day?

Are they failing physically, or getting corrupted?

failure is something we will be able to inform you of in advance soon, the next version of SoftRAID will be able to query disks better (for extended SMART data, which is used to predict failure) in most USB 3 enclosures.

If just corruption, it could be the enclosure. Is this a "hardware RAID" enclosure that you are using with SoftRAID? We have found some of these lower cost hardware RAID enclosures don't handle the extra I/O load very well.

Failing as in OSX can't mount them anymore or a partition has been lost.

This was pre-SR, in an Orico USB3 enclosure which had been okay for many years (like the hard drives that were all bought on the same day). I'm not going to try to use Raid on these enclosures, I'll probably throw them out - I just bought two more TB4 enclosures from the OWC garage sale.

Disk Warrior can probably recover your volume.

Thunderbolt enclosures are a far better option, yes!

Thanks, I bought Disk Drill because the preview from the demo version looked encouraging, and Disk Warrior doesn't have a demo/ trial version. DD is slow though, it's taken 3 days to get to 11% of writing a DMG image.

As an aside, these Seagate Iron Wolf Pro disks with the Data recovery warranty - are they worth trying?

Another question. I now have a few drives that SR predicts will fail soon. The Scrooge in me wonders if I can use them for non-crucial applications for a while. Eg I bought a OWC drive dock which holds 2 drives and has TB connection. So if I do something like a mirror RAID where I will still have access to data unless both drives die at the same time, would that be something stupid? I should just bin these drives now?

Thanks, I bought Disk Drill because the preview from the demo version looked encouraging, and Disk Warrior doesn't have a demo/ trial version. DD is slow though, it's taken 3 days to get to 11% of writing a DMG image.

As an aside, these Seagate Iron Wolf Pro disks with the Data recovery warranty - are they worth trying?

Recovery by scraping data can take a while. It is a slow process.

Disk Drill and Disk Warrior have very different functions.
Disk Warrior is when the directory is damaged (or in poor health) and it can rebuild it. Data does not have to be copied off the volume and in most cases, it recovers all data intact, with all the folders, etc, by replacing the damaged directory with an optimal directory.

Disk Drill (and other recovery apps) scavenge the volume to find files, so you can copy them off. THey work best when the directory is too badly damaged for Disk Warrior to repair, or when a volume has been erased or deleted. The downside of most recovery apps, is if you have a volume that Disk Warrior is unable to recover from, the resultant recovered files are generally "unstructured", meaning no file names folders, etc.

Drives that are predicted to fail may last days, or months. They can be used, yes. Just do not keep mission critical data on them. Or they can be secondary/tertiary back disks.

I also wanted to answer your Seagate Iron Wolf question;

We have not seen recent data with the Iron Wolf series to reliability, but we expect them to be reliable. Early reviews have been favorable and prices are aggressive.

The data recovery policy may not apply to RAID volumes. Their terms indicate they offer a 2 year "1 in lab" recovery attempt. We could not confirm their recovery policy, but it seems to be written to not support RAID volumes, perhaps unless multiple disks fail.

You can check with Seagate about this warranty (and whether they support Macs, and in particular RAID volumes, and report back to the forum, I am sure other readers would be interested.

One trend we have seen with disk manufacturers is restricting warranty terms to limiting the amounts of "TB/year." We understand this idea, but it seems like telling a user "if you use your iphone a lot, it won't be covered under warranty."

Thanks. My enquiry to Seagate about the recovery warranty seems to show that they are not too familiar with the whole concept themselves. My followup to their brief initial response is awaiting answers.

I chose Disk Drill over Disk Warrior simply because it had a demo whilst the latter didn't; the DD demo also seemed to perform better than the demo of EaseUS data recovery, which could only show a few dozen files on a disk that should have hundreds if not thousands of files. The scan is now 14% and seems to have accelerated, possibly this is a less damaged part of the drive.

Good luck getting your data recovered!