[spuggy]

RAID5 has been dead and gone for practical purposes for almost 10 years; pretty much happened when drive sizes went over 1-2TB. The likelihood of another drive from the same batch dying as you stress the survivors trying to resilver the replacement is, well, likely to the point of being almost inevitable.

And that is catastrophic; there is no way to come back from losing 2 drives in RAID5. This seems like a good time to mention that using RAID is no substitute for backups for things you cannot afford to lose...

Not to mention array rebuild time - especially if you're trying to keep the host online/active - increases exponentially, to the point that you're severely impacting/degrading performance for significant periods. Remember, it has to read all the data that's left, calc parity, and then write it to the new drive. Can take dozens of hours for larger arrays.

RAID6 (two parity drives) is a better bet. Although RAID10 (striped, mirrored) will out-perform it, it isn't quite as resilient - you can lose up to 50% of the drives in RAID10 and not lose data - but only if you lose the right 50%... Whereas with RAID6, you can lose any 2 drives out of every group (the size of which, typically, you don't want going over a certain number anyway - let's say 8 is best for throughput, just for the sake of argument).

RAID 50, or 60 - (mirrored RAID5/RAID6) is also an option.

I'd suggest you buy an LSI (now called Broadcom, Avango) card - I have many of these, and they work flawlessly. Unlike some cards, LSI HBAs let you use drives in JBOD mode transparently/without lots of hoops - and SMART pass-through for diagnostics/monitoring/tests Just Works.

I almost never use hardware RAID on these cards - because ZFS is more featureful (only filesystem that writes checksums for files, and allows you to scrub/fix them before you lose data). But the hardware RAID kinda works. Until you lose a drive and test the SMART attributes to realize that almost all the drives are tottering/about to die... Those Barracudas were the last Seagates I ever bought... Shrug.

LSI cards come in all sorts of models - from HBAs (just interfaces to the drive), to RAID firmware on the same card, right up to hardware RAID cards with a dedicated CPU and cache RAM on-board that's almost like a year 2000 PC... Don't use cache RAM without battery backup, BTW... The same hardware is also branded by folks like Dell, IBM, HP, Lenovo etc.

The hardware RAID controllers all look pretty silly now IMO - in light of modern CPU speeds and RAM sizes.

For your usage, I'd say an LSI 2008 (9201-8i) card would be fine; cheap as chips. Flash any firmware you want on them. A 93xx or 94xx card would give you a faster chipset and 12GB/s SAS/SATA interface speed - but frankly, it's spinning rust @ 7200 RPM - interface speed is unlikely to be your limiting factor here, LOL...

Beware no-name Chinese SATA/SAS breakout cables, because there's nothing worse than finding you've got issues with CRC and other errors that look like flakey hardware after multiple weeks of uptime. Find a SuperMicro cable that does the job, it's about twice the price of the no-name (hint: almost always cheaper directly from the SuperMicro eShop than on Amazon or Flea Bay) - but they test it and it will work. I had to swap out multiple HBAs, caddies, enclosures - and swap multiple drives around - before I believed it was the cables. But the problem has never come back and its been several years now...


Oh, and if you didn't already know, avoid providing 3.3V to pin 3 on that drive, either by masking the connector on the drive off, masking it off on the interposer, or by using cables that don't power it (eg SAS breakout cables powered by a Molex power connector - which can only provide 5V/12V, and thus don't power pin 3). Otherwise it'll be stuck in a permanent reset and the drive will never power up (caught me out when I picked up some 8Ts recently and naively plugged them in with an HP SAS/SATA interposer - and then sat around scratching my head going "WTF?" for a while).