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jollymon6672

macrumors newbie
Original poster
Jul 2, 2014
5
1
Aldie, VA
I have 2 Mac Pro's, 2008/2012, and I am looking to hook up a Omnistor SE3016 16 Hard Drive 3.5" Bay Expander SAS SATA JBOD Rackmount. I need recommendations on that will work for this.
 
I have 2 Mac Pro's, 2008/2012, and I am looking to hook up a Omnistor SE3016 16 Hard Drive 3.5" Bay Expander SAS SATA JBOD Rackmount. I need recommendations on that will work for this.

Atto gear has always been the go-to fro mac and I've personally used an R348 which was awesome. Their support team is great.

I'm currently using an Areca card which would be my second recommendation as they are a bit cheaper, quality is good and tech support is almost as good as ATTO.

You'll need a card with 2 x SFF 8088 connectors. Just make sure you get a proper hardware ROC (raid on chip) card. A non-raid HBA (although tempting at about half the price) won't give you the same reliable configurations as a true raid card.

I would look at:
Atto R680
Areca ARC-1882x
 
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Thanks for the fast reponse...

Atto gear has always been the go-to fro mac and I've personally used an R348 which was awesome. Their support team is great.

I'm currently using an Areca card which would be my second recommendation as they are a bit cheaper, quality is good and tech support is almost as good as ATTO.

You'll need a card with 2 x SFF 8088 connectors. Just make sure you get a proper hardware ROC (raid on chip) card. A non-raid HBA (although tempting at about half the price) won't give you the same reliable configurations as a true raid card.

I would look at:
Atto R680
Areca ARC-1882x

I noticed a ATTO H680, do you know the difference? With the dual ports, it states they support up to 8 devices. Does that mean I need two card for a 16 bay unit or does the unit act a one drive?
 
I noticed a ATTO H680, do you know the difference? With the dual ports, it states they support up to 8 devices. Does that mean I need two card for a 16 bay unit or does the unit act a one drive?

There must be a SAS port multiplier inside, as there is only only one outgoing SAS port on the unit.

A H680 HBA (Host Bus Adapter) is designed as a passive interface with external RAID arrays that manage the RAID using hardware in the external box.

As your Omnistor box is a simple JBOD (just a bunch of disks) system, you will need an R680 RAID card to manage the raid for you.

Both situations work the same, it just depends on which end the RAID is managed at.

Just to add something else into the mix - a passive HBA (e.g. H680) will technically work with a simple JBOD expansion box (your Omnistor)

BUT

You won't get true RAID functionality and your data is essentially unmanaged and vulnerable to failure should any of your disks die. I would not recommend this.

A true RAID system offers a combination of:
1. Speed - All disks work together, as opposed to the full load being placed on one disk at a time
2. Redundancy where one or more drives can fail and your system keeps working while you swap the disk

What RAID level you choose is up to you. For a 16 bay system, it's typical to use RAID 6 plus 2 hot spares.

This means up to two drives can simultaneously fail and they will be rebuilt using the hot spares, leaving no interruption to your work at all. However 4 of your disks are used for redundancy, leaving 12 for actual storage.
 
I would look at:
Atto R680
Areca ARC-1882x

The R680 looks like a good choice. Note that it has http://www.attotech.com/features/CacheAssure/ - technology so that a supercapacitor can save dirty write data in the cache to flash on power failure. You don't want to run RAID 5/6/50/60 without some assurance that your recent writes won't disappear if the power fails. (And you don't want to run RAID 5/6/50/60 without the write-coalescing that write cache gives you.)


There must be a SAS port multiplier inside, as there is only only one outgoing SAS port on the unit.

SAS provides a generalized switched fabric that is far more flexible than the limited SATA port multiplier stuff. At SAS prices, all of the cabinets/controllers that I've looked at have the switched fabric.

The R680 specs say that 256 drives are supported on the 8 SAS ports.

Also note that the R680 has two connections, each of which has 4 SAS lanes. One connector - 4 lanes. One lane - 32 disks. Four lanes - 128 disks. Eight lanes - 256 disks.

My HP SAS cabinets/controllers support 256 drives per lane.
 
Last edited:
There must be a SAS port multiplier inside, as there is only only one outgoing SAS port on the unit.

A H680 HBA (Host Bus Adapter) is designed as a passive interface with external RAID arrays that manage the RAID using hardware in the external box.

As your Omnistor box is a simple JBOD (just a bunch of disks) system, you will need an R680 RAID card to manage the raid for you.

Both situations work the same, it just depends on which end the RAID is managed at.

Just to add something else into the mix - a passive HBA (e.g. H680) will technically work with a simple JBOD expansion box (your Omnistor)

BUT

You won't get true RAID functionality and your data is essentially unmanaged and vulnerable to failure should any of your disks die. I would not recommend this.

A true RAID system offers a combination of:
1. Speed - All disks work together, as opposed to the full load being placed on one disk at a time
2. Redundancy where one or more drives can fail and your system keeps working while you swap the disk

What RAID level you choose is up to you. For a 16 bay system, it's typical to use RAID 6 plus 2 hot spares.

This means up to two drives can simultaneously fail and they will be rebuilt using the hot spares, leaving no interruption to your work at all. However 4 of your disks are used for redundancy, leaving 12 for actual storage.
[doublepost=1496760733][/doublepost]I know it has been ages since this thread was active, but I came across it again and wanted to express my thanks to all who provided solutions. It worked out great!
 
Hello, I have a question about the Atto R348 pcie card, does it still work under High Sierra and El Capitan?I'd like to buy a cheap one, for my 5.1.
On the Atto's website, it seems there's just old drivers.

Guillaume
 
Hello, I have a question about the Atto R348 pcie card, does it still work under High Sierra and El Capitan?I'd like to buy a cheap one, for my 5.1.
On the Atto's website, it seems there's just old drivers.

Guillaume

Yes, I am running 2 16bay units on the recommended card on El Capitan.

Thanks to all for the help.
 
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