SAS or Thunderbolt

[Bob Zelin]

the 8050 is your best choice at the moment. But as you know, things will change in the next few months.

Bob Zelin

Bob Zelin
Rescue 1, Inc.
maxavid@cfl.rr.com

[Alex Gerulaitis]

ARC-1200 series don’t support SAS expansion, so no 8040 with that controller. 1800 series.

Other than that – it’s a personal choice. TB boxes are as “dead-end” as SAS non-expanders: with RAID6 and hot spare – 62.5% efficiency. If not worried about efficiency or flexibility (of, say, only array expansion and other niceties of decent RAID controllers) – then 8050 it is.

— Alex Gerulaitis | Systems Engineer | DV411 – Los Angeles, CA

[Neil Sadwelkar]

Thanks Alex. I think I’ll wait for the 8050.

I didn’t get the dead end part with Thunderbolt. Or the 62.5% drop in efficiency with pass-through. What’s that exactly?

And how does array expansion work with SAS ? How’s it different in Thunderbolt?

———————————–
Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India

[Alex Gerulaitis]

I was wrong about 8040. It’s the 4036 that ARC-1223 is not supposed to work with – at least not the SAS expander part – but you say it’s bundled? I’ll look into that.

A RAID controller isn’t required with 8040, just an HBA. 8040 supports SAS expansion (up to 122 drives via add-on boxes like 4036) – so that might be a good option if you need more than 8 drives in a RAID set.

[Neil Sadwelkar] “I didn’t get the dead end part with Thunderbolt.”

Can’t expand a RAID set beyond the number of drives in the box – at least not with Pegasus and Areca boxes.

[Neil Sadwelkar] “Or the 62.5% drop in efficiency with pass-through. What’s that exactly?”

Create a RAID6 set with a hot spare with eight drives. Two drives used for parity, one for a hot spare. That leaves five drives worth of usable space – or 5/8th space utilization efficiency (SUE) – or 62.5%. Create a similar set with 16 drives and your SUE goes up to 81.25%.

I.e. a maximum of 8 drives in a RAID set can be limiting in other ways besides capacity and performance.

Something tells me there will soon be TB2 arrays with built-in SAS expansion.

[Ricardo Reyes]

Alex, Let me clear up a few things.

The ARC-4036ML is a non-expander JBOD Enclosure and requires an ARC-1223-8X RAID Controller. Supports only 8 drive max per controller.

The ARC-4036 is the expander version which requires an ARC-1882X RAID Controler that supports SAS Expansion and allows you to support more than 8 drives by daisy chaining additional ARC-4036 JBOD expander units.

The ARC-8040 has the RAID controller built in and requires just a SAS host card like the ARC-1320-8X. The ARC-8040 also supports SAS expansion allowing it to work with ARC-4036 and daisy-chain addtional storage to fit your needs.

Ricardo Reyes
Areca Technologies – US Channel
Ricardo@ArecaUS.com
http://www.Areca.com.tw

***** RAID is not a substitute for proper and regular backups *****

[Alex Gerulaitis]

[Ricardo Reyes] “Alex, Let me clear up a few things. “

Thanks Ricardo! I was hoping you’d chime in… 🙂

Forgot about the non-expander “ML” version…

TB2 version of 8050 a coming? Before Xmas, right? 🙂

Do you think there will be a version of 8050 with SAS expansion sometime in the future?

[Ricardo Reyes]

That would be a nice xmas present for everyone…sorry to disappoint. The Areca TB2 8bay is said to be available February 2014, around the same time when Apple starts shipping out the new Mac Pro backorders. =) Keeping my fingers crossed.

Ricardo Reyes
Areca Technologies – US Channel
Ricardo@ArecaUS.com
http://www.Areca.com.tw

***** RAID is not a substitute for proper and regular backups *****