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Best use of Thunderbay 8 and SR

(@chobochobo)
Estimable Member Customer

I'm currently running a set of Thunderbay IV TB2, RAID 5 with carbon copy clones as 'backup'. I'm mostly creating a store of files - I'm getting into Hi Res audio and recording video. I don't do much processing except some trimming, so I'm looking for a reasonable speed and reliable storage, I think. 

I see the Thunderbay 8's and think great, more disks, more storage. Am I right in thinking a big RAID 5 wouldn't be great with 8 drive enclosures. Perhaps a RAID 1+0 with a 8 drive '1' and 2 sets of 4 drive TB4's being the '0", as it were? Would the mix of thunderbolt 2 and 3 create any issues? I bought Apple adapters which have so far been ok for connecting my TB4s to my new (refurbished) Mini 2018 after my MacPro 2013 died.

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Topic starter Posted : 04/09/2020 8:36 pm
(@softraid-support)
Member Admin

The 8 bay is good value, yes. You can either do a large single volume, or I have seen many users make 2 RAID 5 volumes on them. The Apple adapters seem to work great!

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Posted : 05/09/2020 1:14 am
(@chobochobo)
Estimable Member Customer

During a google search, people seem to recommend RAID 6 for 8 drives. There seemed to have been a RAID6 once with Softraid? 

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Topic starter Posted : 09/09/2020 3:05 am
(@softraid-support)
Member Admin

We are working on RAID 6 but do not have it in SoftRAID yet.

Note: There is a huge misunderstanding in RAID 5, thinking it is "failing" with large drives. We performed some tests, of constant IO to a 15 drive RAID 5, with intensive IO for a year. Not a single "bit rot". We also rechecked their math, and believe the original claimants about RAID 5 is doomed did the math wrong. (by an order of magnitude)

We think perhaps that PC hardware is generally lower quality than Apple hardware. We did a similar test with RAM, where we should have expected one ECC error a month, and we saw zero for a year.

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Posted : 09/09/2020 6:15 pm
(@desertnomad)
Trusted Member Customer

I am concerned about the strenuous rebuild of RAID 5 so with my TB8 I am setting it up as two RAID 1+0 volumes with 4 drives each. Yes, I lose half the space (vs 25% with RAID 5) but I think RAID 1+0 will rebuild much more reliably than RAID 5. I think the writing to RAID 1+0 will be faster too as there is no parity to calculate (though there is mirroring).

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Posted : 03/10/2020 12:06 pm
(@softraid-support)
Member Admin

RAID 5 is faster, as there is 3 disks of data, rather than 2 per pass.

Rebuilds do not stress drives. An example is the google study of 100,000 disks, where there was no difference found in failures between "light duty" and "heavy duty" disks.

 

But you need to configure your drives so you are 100% comfortable with them!

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Posted : 04/10/2020 11:33 am
(@desertnomad)
Trusted Member Customer

Many articles point out the advantages of RIAD 1+0 over RAID 5 in terms of rebuild (and write speed).

https://www.acronis.com/en-us/articles/whats-raid10-and-why-should-i-use-it/

Wondering if anyone here has seen a failure when rebuilding a RAID 5?

 

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Posted : 22/10/2020 2:33 pm
(@softraid-support)
Member Admin

Be aware that many writers are comparing hardware RAID. RAID 5 hardware is incredibly slow during rebuilding.

RAID 1+0 is slower, but easier to recover from in an emergency and 50% of the time can handle 2 failed drives (out of 4)

SoftRAID has fast rebuilds, so the risks are much lower of a second failure during a rebuild than any hardware RAID.

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Posted : 22/10/2020 9:44 pm
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