Similar 1U enclosure with 2x SFF-8088 for daisy-chaining?

[integrase]

Greetings,

I have been asked to set up and install a storage server but due to constraints related to available space and esthetics in the ongoing renovation, the home network is being installed in a wallmount rack. I have a total of 21U vertical space but depth from front of rack to wall is approximately 14 inches. 15U is available to work with as the remaining space is taken up by the switch, a pfSense box and 4x CyberPower UPS units.

A NAS solution like Synology's 1813+ is not being considered because the owner wants to move away from Synology after a couple of bad experiences and because the non-corporate units (which would fit in the available space) don't offer the storage density being asked for.

I have found two similar 4-bay SAS enclosures which have the right physical size and are relatively low-cost but have only a single SFF-8088 port:

GAGE104U40BK-MS - Build-to-Order - 1U 4x3.5" Trayless miniSAS SFF8088 Enclosure 150W Black

Addonics Product: 1U RAID Rack with mini SAS, SFF-8088 (R1MSAS)

Has anyone seen anything similar but with two SFF-8088 for daisy-chaining units together?

My other options are to use 6 Sans Digital MobileStor MS8x6 (MobileSTOR MS8X6 - 8 Bay SATA/SAS to 6G SAS Expander JBOD Enclosure) for 48 drives, or to vertically mount something like Sans Digital's EliteStor 3U units for 32 drives. Both of these are pricier and the vertical mount is much less desirable due to space constraints and really having something cook underneath.

 

[dba]

A disk enclosure that includes two SAS ports, one of which can be used for chaining, implies that the unit has a built-in SAS expander. I don't know of too many 1U four-disk enclosures that include an expander, and one that is also just 12" deep is extremely unlikely to exist. Also, your last sentence says that you looking for 48 total drives. At four drives per enclosure, that would mean 12 SAS expanders, which would get very expensive. Even if it existed and wasn't expensive, you'd have one seriously long chain of cables to worry about.

Another approach that doesn't vary too far from your original ultra-low-depth design would be to use non-expander enclosures like those you selected, but all connected to one or more other enclosures containing multi-port expanders, which in turn connect to your server. Imagine an empty 1U box that contains a power supply and a SAS expander with all of its ports routed out the back as SFF-8088 ports. Connect two of the expander ports to your server and then connect the rest of the ports to your 1U disk enclosures, forming a nice expander-based "star" network instead of a daisy chain. That would let you use your short-depth 1U non-expander enclosures but give you the expanders that you need. Unfortunately, you'd probably end up needing several of these home-grown 1U expander enclosures because of the real estate needed to route the SFF-8088 ports out the back. That brings up an even better solution:

My favorite design would be an LSI SAS switch, which would let you connect up to 14 of your 1U encloses to a server. I'm not 100% sure that the LSI will work when connected to non-expander disk enclosures - it should work, but it's not a normal use for this product - but if it works then it would be a very clean solution, even providing you with web-based management of the expander itself. Search for SAS6160 on SAS switch on eBay if you are interested - one of the listings will be my auction. You'd also want the 1U rack mount for the switch.

 

[integrase]

Thank you for the reply. I have seen the LSI switch while doing research for this project, but I think we'll have to drop that idea because of the "it should work" aspect. The daisy chains wouldn't have been that long as I was going to use a 4-port LSI controller to limit the chain to no more than 4 enclosures per port.

By thinking about it again, the best mix might be 3x Sans Digital MobileSTORs and 4 of the 1U enclosures, which would provide 40 drives in 11U space.

 

[dba]

Thank you for the reply. I have seen the LSI switch while doing research for this project, but I think we'll have to drop that idea because of the "it should work" aspect. The daisy chains wouldn't have been that long as I was going to use a 4-port LSI controller to limit the chain to no more than 4 enclosures per port.

By thinking about it again, the best mix might be 3x Sans Digital MobileSTORs and 4 of the 1U enclosures, which would provide 40 drives in 11U space.

If you are interested in the SAS switch that I have for auction, that is to say that if the switch is your preferred architecture except for the compatibility question, I'm willing to run a test for you. I expect that it will work perfectly - the LSI expander upon which the 6160 is based is very commonly deployed this way - but I always try to be explicit about I have actually seen working versus what should work.

If the daisy chain/snowflake is, instead, your preferred architecture, definitely - I mean definitely - buy your parts with a good return policy. Cascading expanders can be tricky - even though it shouldn't be. Connecting your 1U enclosures to the AccuStor expander chassis is, for example, connecting a non-expander chassis to an expander just as the LSI SAS switch would be doing. In fact, the AccuStor might just be based on the same LSI expander chip as the 6160.

 

[mrkrad]

I am curious how that sas switch would work with an HP mds6000. It is how they reference design the dual C7000 bladesystem but I think the switch might be internal to the chassis? Never seen the sas switch.

The HP Smartarray controllers have zoning built in! But a SAS switch isn't a bad way to go either! I'd love to play with your switch lol

 

[integrase]

Thank you for the offer of testing the LSI switch. I have been speaking with the owner about various possibilities and KISS is having an impact. There's still several weeks before I get started so things might still change but it looks like the two EliteSTORs mounted vertically will be the eventual choice.