Question about Hardware needed to use a Disk Shelf.

ComputerGeek

[H]ard|Gawd
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Hey guy's I am a bit of an idiot when it comes to enterprise server equipment. I am wondering what exactly is needed to make something like a Netapp ds4243 work? Do I need to purchase one of their servers, is it possible to build my own server and put a interface card in it? Just curious as to how disk shelfs work as a whole? Any articles or information that you guy's can point me too would be great.


http://www.ebay.com/itm/NetApp-DS42...065651&hash=item23874a98b6:g:3XUAAOSw-3FZB4pr

Also, I'm sure this will get clearer as I figure out how they work, but are there any issues using these with a freenas or unraid setup? Thanks!
 
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So, not having used the Netapps myself, I can only make an educated guess. That guess is that these guys are essentially SAS expanders. SAS expanders and SATA port multipliers have are roughly analogous to switches and hubs in the networking world; port multipliers work largely like hubs in that devices are not addressed individually and 'divide' the bandwidth of the uplink amongst the ports, whereas switches still allow for individual addressing of each connected device on a port and each port brings its full bandwidth to the equation, obviously still constricted by the speed of the uplink connection.

This "Disk Shelf" looks like an external SAS expander that would plug in via an external SAS cable of some type to a supported controller card. That uplink would be via one of the dual IOM6 or IOM12 modules, which I suspect is Netapp-ese for SAS2 (6 Gbit) and SAS3 (12 Gbit) connectivity. Being true SAS expanders, disks attached via this device would function as if they were directly attached, though the controller card will be aware of the presence of the expander since it communicates along the chain as well.

If you're looking to whitebox something similar for yourself, keep in mind not all controllers support SAS expanders. For example, I currently have in my possession (for sale!) an Areca ARC-1216-4i card, which is a real $375 4 port SAS3 RAID card that does *not* support expanders. Even the 1216-8i card which supports 8 drives does not support expanders. Instead, on the Areca side you have to jump up to the ARC-1883i line to have expander support. As an interesting side note, the ARC-1883ix line is the same card as the 1883i line, except with a built-in expander on the card which allows it to address more than 8 ports. The 24 port card is the same as the 8 port card, just using an expander to get there.
 
I've never used the netapp stuff, but a quick google suggests you *should* be able to use it the way you want, depending on the controllers installed in the DS4243 you'll just need something like a 9280-8e and cables to connect it to the computer of your choice. Be aware, the listing you linked to says no drives but doesn't say whether drive caddies are included... if they're not included you can plan on spending another $80-$100 to purchase them.
 
Looking to pull the trigger on a purchase for a netapp ds4243 as well.

I believe Filecom uses these shelfs. Anyone know if they support 8TB WD Reds? Will it work with FreeNAS and ZFS? Of course I would need to get a raid card that supports this many drives and IT mode.

Thanks!
 
So after much digging I found this post on reddit that was pretty helpful for some of my questions:


I am going to pick one up to test it out.
 
Any update here?
Thinking of getting a DS4243 myself.

Use a SFF-8088 adapter cables ($50) or a Netapp X2065A-R6 controller (ebay $20)... ?!
 
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