RAID 6

Its still in our map, but we have noticed low demand for RAID 6 actually. There are lots of things coming, we may add RAID 6 next year perhaps, but other features are slightly higher on the list. (performance enhancements being a major one)

Posted by: @benthebear

↑

Can anyone point out another macOS / Windows piece of software that can do what SoftRAID does that supports RAID 6 for DAS configurations? 

Not in software. But you can buy DAS enclosures that have it

@syd 

What about Thunderbolt? Maybe USB enclosures are why people want RAID 6. I would never trust USB (at least on a Mac) for critical active data. Apple's implementation leaves too much to be desired.

We did a long running statistical test against "bit rot", which is the main claim for RAID 6. In 18 months, not a single piece of bit rot, on an active volume, or a passive volume, running intensive IO 24 hours a day. We were running a 15 drive RAID 5, on budget Thunderbolt hardware.

I am not sure how many Petabytes we ran in our test, but we essentially proved, at least on macOS, there is no such thing as "bit rot". Most likely a flaw in the paper author's design, or their hardware setup, which was a linux configuration.

By their records, we should have seen more than one bit flip a month (byte mismatch).  We saw zero. in 18 months. We stopped the test, as it was providing zero information at that point.

We found a similar contradiction with Memory testing on MacOS laptops. Dozens of Mac Laptops running a memory tester 24/7. We saw zero "bit flips" on that also. We were expecting that test to fail occasionally, but it never produced a faulty result. Our original plan was to release an app that could do this for thousands of computers (volunteers), but with zero failures in RAM, there was no point in our eyes.

@syd any chance you have a link to a DAS that connects via USB-C with 5-8 hdd bays that has RAID 6 built in? I looked for weeks and could not find one.

Posted by: @softraid-support

↑

@syd 

What about Thunderbolt? Maybe USB enclosures are why people want RAID 6. I would never trust USB (at least on a Mac) for critical active data. 

...

Totally agree with you there! I'm not an advocate for Raid 6, but just answering the OP question. I'm not even much of a fan of Raid 5 these days - Raid 10 is my go to.

This is the DAS that I've come across, but no direct experience:

https://www.terra-master.com/global/d8-thunderbolt-3.html

Posted by: @benthebear

↑

@syd any chance you have a link to a DAS that connects via USB-C...

Not USB-C - that's so bandwidth limited and unreliable. See the Thunderbolt 3 one in my previous post.

Posted by: @softraid-support

↑

we have noticed low demand for RAID 6 actually

You are so wrong about this. I'm quite surprised to see such a statement coming from someone on the SoftRAID team. It borders on gaslighting to say there is no demand for RAID6 after years of shutting down the conversation about it when customers have asked over and over again for years when the feature might arrive. You do recall promising it years ago, yes? There is really no way to excuse such a delay. You would be much wiser to just speak to customers openly and honestly and say the truth: either you can't do it (for whatever reasons), or you simply aren't interested in doing it, and then apologize for not having told us the truth years ago.

We still want SoftRAID RAID6. Lots of people in enterprise environments were looking forward to its arrival when SoftRAID v6 came out. We don't have time to keep making a fuss about it when a company fails to produce what they promised. Long story short: you flaked out, you offered nothing but platitudes and excuses, and we gave up on asking you about it because clearly you are never going to deliver. We own a lot of SoftRAID licenses, and we regret that now.

@bry2k 

As on the other thread, it is still in our road map. There have been other priorities, such as M1, and the other driver changes for long term Apple Silicon compatibility. Those are all completed now. Give it some more time, but it is definitely on the road map.

Glad this is at least still on the roadmap and hopefully with the other changes out of the way this can be accelerated. Three years ago when opting for SoftRAID and choosing hardware appropriately it was done on the understanding that RAID 6 was supposed to be coming soon and RAID 5 would be upgradeable.  So I bought 8x12TB for a Thunderbay 8 and for 3 years I've only had a 7x12TB RAID 5 array in there and a 12TB drive (that cost a premium back then compared to today) in a cupboard doing nothing.  Definitely understand the frustration from others when earlier communication that it was going to be many years away would have let me have larger a capacity RAID 5 to enjoy or buy a different configuration of equipment.

Hopefully SoftRAID 8 is a fresh start and I'm happy to see you seem to have listened to user feedback with the new license/subscription model as the previous iteration really soured me on the product and company having previously been very positive due to interactions with yourself in the forums.

I have wanted to use SortRAID for several years.  However until there is RAID 6 I will not do it.  Even with RAID 10, if the wrong two disks die you are gone; that has happened to me.  RAID 6 is the only RAID solution that tolerates the loss of any two disks.  There is a lot of latent demand that you are not even aware of in the form of people like me who would buy SOFTRAID if it had RAID 6, but are not in your forum or using your product for that reason.  Hope it comes soon.

@davidement 

Its on our map. MacOS has essentially added a few years to its arrival, with all the driver changes. Those changed are slowing down, so hopefiully we will have it sooner than later.

This is a follow on to my request from September.  I am about to set up several storage systems and several other people will be doing the same in parallel.  In addition I have a software product that benefits from accessing advanced storage systems.  If I could I would use, buy and recommend SoftRAID.  The problem is that I need RAID 6.  In a different world I would use SoftRaid and count on or at least hope for RAID 6 coming out.  However, given that you have been saying you would do it for several years and there is no hint or indication that it is really coming, let alone a time frame, I am basically forced to go in a different direction.  I hope you hear this.  The ability to tolerate the failure of two, not one, drives continues to be critical.  Your product is so great in so many other ways . . .

@davidement 

RAID 6 is under development. But it is at least a year away.

Note that with predictive failure, getting two failures at the same time is extremely rare. Much more rare that the odds of losing the volume from file system damage.

There are many "claims" about RAID 5 being dead, i.e, the volumes are so large that the parity data is mathematically going to fail frequently (monthly is about the claims I have seen). As a result, we did some math and felt that those authors did not understand error correction very well and errors should be far more rare.
So we did a test. Took two RAID 5 volumes, one actively uses, the other with random (verifiable) data, but static, so we could check for "flipped bits".

these two volumes ran for 18 months, 24/7 and not a single data error was found over 18 months.

"RAID 5 is dead" postulate is debunked.

Thank you for the prompt reply.  For me it is a little scary and maybe sad that your RAID 6 is at least a year way, but so be it.

For what it's worth, I started programming in 1966 and have been around storage devices since then.  I happen to have six RAID arrays myself; in my business there are more, and I can't even imagine how many there are across our customer / subscriber base.  There is the mathematics and arithmetic (was on my way to be a mathematician at one point) and then there is the reality.

Disks fail; particularly rotating disks.  Personally there is no year, these days, in which at least one disk does not fail somewhere across my various configurations.  I have had two disks fail within a RAID configuration a few times (less than five, but more than one time) over the past, say, eight years.  And, one time, but one time only, I had three disks fail within relatively short order.  I believe some of this may be related to whether sets of disks were bought at the same time; then if there is a materials or manufacturing problem, several units could get hit at the same time.

With RAID 5, I would have lost my RAID array a few times over the past few years.  With RAID six it only happened once, and might not happen again in my remaining lifetime (which sounds ominous but isn't at all, really).  Now in my case, if I were to lose a RAID array I would not lose any data, but the primary software I use replicates continuously so when I lose one RAID array I rebuild from the others.  The problem is that most of the RAID arrays are used all the time, so when they go it is inconvenient and could cause some things I do to run much, much more slowly.

So, I am glad you are eventually going to get RAID 6 done.  At this point, from the time of that comment saying "one day", to the point of completion it will be many years, but that is better than never.  I'll end by saying, I hope you can raise it in priority so it gets done sooner, but I truly thank you for your intelligent responsiveness.