Dual port SAS JBOD enclosures?

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danswartz

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So I've been happy with my SE3016. One 8088 SAS in on the front and one 8088 SAS out to daisy chain to another enclosure (which I don't have or want.) I'm wondering how feasible it would be to replace the current expander PC card with a dual port? I saw a thread about that (I think), but it involved adding two new connectors to the front of the unit. I'm wondering if it isn't possible (somehow) to replace the expander and connect the two ports to the SAS in and SAS out connectors? If not, what ideas do folks have for something similar?
 
What your asking is not very clear.

Replace with a dual port? you mean you want to use dual ported sas drives? not possible.

Replace the expander with another dual port expander? sure, but the layout of the ports is odd, so alittle hard to match it up.
 
Now I am totally confused. I thought that SAS drives had dual ports? Or do you mean the SE3016 expand doesn't support two ports? If the latter, I understand. I thought that was in fact the case, so I was looking into replacing the expander with one that did (and if it required some surgery to expose the two 8088 ports, I'll live with that...) Is that clearer? Thanks!
 
OP wants to know how he can swap out the 3 Gbps SAS expander in the SE3016 with a 6 Gbps one.

What you would need is either a 6 Gbps SAS expander that is powered by Molex or a burner motherboard you can install to deliver power to the PCI bus of the card. No CPU or memory required. Then you probably need a SAS converter backplate to run some internal cabling up to where you will expose your 8088. I do not have the 3016 or I would send pictures.
 
You would need to replace all the backplanes as well since they presumably only have a single port connected. Not really sure why you need access to both ports though, but if you really do, you should just buy a Supermicro chassis.
 
I am trying to figure out a good way of having HA storage. Everything else I have looked at has been problematic. e.g. drbd, glusterfs, etc, all entail some sort of CDP replication and having to do failover IP to access the new location. The copying of data sucks performance-wise (e.g. the writes.) I have been told one way to do this is with a dual-port SAS enclosure - two storage appliances, each with an HBA connected to the JBOD. Only one has the pool imported and active. If you need to failover, the unit that takes over, imports the data pool, updates the iSCSI config, takes over the virtual IP and you are good to go. I understand the actual JBOD is still a single point of failure but that is less of a concern than in my current setup (where I have one storage appliance, with data backed up hourly to a backup pool - if the main storage appliance fails, I am down...) It's entirely possible this isn't worth trying to do with the HW I have at present... I appreciate the input :)
 
Dualport with bargain bin SE3016? Not gonna happen.

You do realize the disks have to be dualport too, yes?
 
Sorry, I don't remember what I have posted where :) These are 8 nearline SAS 1TB drives, so they should be dual-port, no?
 
Looking around on ebay, I happened to find this:

http://www.ebay.com/itm/Areca-ARC-4...US_Drive_Enclosures_Docks&hash=item35c44553b6

It has the exact number of drives I need, and 2 SAS in connectors. I'm not 100% sure of whether this will do what I want, since the docs I've seen refer to connecting two cables to the same HBA, for higher throughput, whereas I want to connect each connector to a different HBA in different servers. I don't know why that wouldn't work, but I freely admit I'm still learning this stuff. I appreciate the helpful suggestions folks have been making...
 
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danswartz said:
Looking around on ebay, I happened to find this:

http://www.ebay.com/itm/Areca-ARC-4...US_Drive_Enclosures_Docks&hash=item35c44553b6

It has the exact number of drives I need, and 2 SAS in connectors. I'm not 100% sure of whether this will do what I want, since the docs I've seen refer to connecting two cables to the same HBA, for higher throughput, whereas I want to connect each connector to a different HBA in different servers. I don't know why that wouldn't work, but I freely admit I'm still learning this stuff. I appreciate the helpful suggestions folks have been making...
Click to expand...

Super expensive and only supports 2.5" drives. I guess if you needed high IOPS scratch space but most are looking for the $/GB that 3.5" drives can offer.
 
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G4VEL said:
Super expensive and only supports 2.5" drives. I guess if you needed high IOPS scratch space but most are looking for the $/GB that 3.5" drives can offer.
Click to expand...

The 4036 supports 2.5 & 3.5 drives, we have a couple of them on various boxes.
 
Super expensive? It's like $900, which includes enclosure, expander (dual-port), power supply, etc... I've been looking at other alternatives, and they all seem to add up to several hundred bucks anyway, even the roll your own types.
 
mwroobel said:
The 4036 supports 2.5 & 3.5 drives, we have a couple of them on various boxes.
Click to expand...

Are you happy with them? Can I in fact plug HBAs from two different servers into one and access the disks either way? (I realized I have to coordinate access to them to avoid corruption...)
 
I looked at a bunch of SM units, and it seemed like they either were way oversized (24+ drives) or way expensive ($1300 or more...) Maybe I'm not looking at the right units? What do folks suggest?
 
There are two issues here.

First is, you don't have to have dual sas paths, to connect to hba's. It depends on the disks and expander how many hba's you can connect on a single path, normally it is 16 or 32.

The dual sas paths is mainly for redundancy as far as a broken cable goes, not cause it's required for two different computers.

Now, the sas1 expanders, might be limited in this usage, I know they do some odd fanout thing, but the sas2 expanders removed all those odd limitations. So I would test two hba's into the se3016 first, see what happens. If it's not working, I would go with a supermicro 6g unit. E26 model numbers are dual expander sas2 (dual expanders gives you the dual paths from the disks).
 
Hmm, interesting. I wasn't aware of that, thanks. How would you connect two HBAs to a single SAS-IN port then? Some sort of adapter?
 
That is what I meant, SAS1 expanders have in, out, cascade ports. How much it really cares about this, is vender specific.

With SAS2, all those ports are the same, they are only named, to help people not screw up, not cause they are different.
 
Sorry, I'm not being clear. You said to try 2 HBAs and see how it works. My 3016 has a SAS-IN and SAS-OUT on the front panel. The latter being documented as being for daisy-chaining. Are you saying I should try plugging another HBA into the SAS-OUT port and see if that works? If so, I should be golden?
 
Yes, that likely will work.

I can't say 100% with a sas1 expander, but it would with a sas2 expander. Looks like it's supported with sas1 with some limitations, but those are not easy to figure out, unless the documentation you have, describes it.
 
Unfortunately the SE3016 documentation is scanty, to put it politely :) I will just have to scrounge another 8088/8088 cable and give it a try. I'll post back my results. Thanks!
 
Good news (so far at least.) Cable showed up. I have an 8087/8087 cable and pci bracket with 8087 internal/8088 external already, so I was just waiting for the 8088 cable. Came today. Plugged in my m1015 to a spare box and booted into LSI bios. Plugged one end of 8088 cable to bracket and the other to the SAS-OUT port on the se3016. 8 SAS drives detected! I need to install a real (minimal) OS to make sure I can really talk to the drives, but so far, looks like I'm saved $X here :)
 
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