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How to use a SoftRAID startup volume with High Sierra

If you're using High Sierra, and booting up from a SoftRAID volume, you'll need to follow the steps given in this forum post, since the macOS High Sierra Installer does not recognize SoftRAID volumes as valid startup volumes.

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SoftRAID Easy Setup and Certification
I just setup a Thunderbay 4 RAID enclosure (Thunderbolt 3) with four 8TB disks (which I provided) and used the Easy Setup application to perform the initial configuration. I was surprised that at no point during the process did it prompt me to certify the drives.

Before I purchased the Thunderbay I did a lot of reading about SoftRAID, and it seems certification is a highly encouraged, if not required step to ensure the quality of new disks. Did I miss a step with Easy Setup? Should I go back and certify the disks using the main SoftRAID XT application? I'm a little hesitant to embark on a multi-day process if it's not entirely necessary, especially since I need the storage sooner rather than later.
Easy Setup does not require certification, as it is a multi-day event. Most users purchased disks with their Thunderbay, where they are already run through a certification process.

The reason certify is so useful, as drives are shipped untested. Lets say a small percentage are faulty at some location on the drive. You will not discover that until you fill up, and need to read or read/write from that location, which could be months in the future.

A certification can reduce the amount of "DOA"s by 90%, as you catch such flaws on the first days of use.

Another advantage of catching this up front, is a DOA is treated differently than a drive that fails under warranty which is replaced by a "refurbished" drive. DOA are replaced by "new" drives.

So if you can, do certify the disks. 8TB drives will take 3-4 days, however.
One more question regarding certification of the new disks. Do you have any statistics regarding how many passess it is recommended to go through?

Does the first write/read process show most of the DOA disks?

Is it a big difference between 1 pass and 3 passes? 10TB Ultrastar takes a couple of days...
You must perform at least 2 passes at minimum for a certify. this is because what we do is write out a random pattern of data and read it back. But the last pass is "Zero" so the drive is restored to the factory new state.

This means a single pass is only a zero disk command and a read command (verify disk), which does not tell you if the drive can be read reliably. (if a drive has all zero's, and you are reading it back, it will of course have little problem reading zero's.

the reason 3 passes is optimal, is then each sector of the drive gets a combination of read requests that are different, followed by a "zero" out of all sectors, which the final read will verify completed correctly.

More passes are redundant, unless you are erasing a disk with sensitive data.

One additional comment on certify:
A disk should NEVER fail a certify. While a failure could be caused by the disk, the enclosure, cable, power, etc, what it really indicates is your "subsystem" is not capable of reliably writing, storing, and reading back data.
Bottom line is if you get a certify error, even if it appears to be non disk related, be very cautious putting that system in active service, as it has proven not to be reliable.
If time is a heavy factor, try a 2 pass certify.

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