VSAN6 - Where can I find information compatible JBOD enclosures and external SAS cards?

[DanielSalzedoSA]

I am working on a VSAN6 build for our environment which consists of Dell R720 servers with PERC H710P cards. They already have their internal disk bays full with local drives being used as both the ESXI boot drive and local a datastore. To avoid disruption I wanted to leave these drives in place. VSAN v6 says it allows for external JBOD enclosures so I my plan is to add a SAS JBOD shelf to each R720 and a PCIe SAS controller with external ports to each host. The plan was for the JBOD shelf to have 1xSAS SSD and 7xSAS HDD. I was looking at using something like the Supermicro SuperChassis 825TQ-R740LPB for the JBOD shelf.

However once I started consulting the compatibility guide (VMware Compatibility Guide: vsan) I became very confused for two reasons:

1. No JBOD enclosures are listed at all. It's not even a search filter option. Does this mean VMWare don't care at all about the enclosure, or are these listed somewhere else other than in the main Compatibility Guide?
2. All the I/O controllers listed with external SAS ports (EG The LSI SAS9207-4i4e) have the following in the the Model Release Details/Footnotes: "Virtual SAN 6.0 can only support internal drives and cannot be used with the external capabilities of this controller". How can VSAN6 use external JBOD enclosures when none of the supported I/O cards support connecting external drives?

Thanks.

[depping]

Good question, I will ask the PM to comment here what is planned / coming... if he can talk about it publicly that is.

[jwhitehv]

Oh thank goodness. I thought I was the only one who was thinking this. Any updates depping‌?

[jonretting]

I have tried a plethora of LSI based SAS HBAs on 6.0, but have yet to get one to work with any external SAS connection. Would really like to get some official information on this, thanks OP for bringing this up. And especially thanks to Duncan grabbing this ball.

[DanielSalzedoSA]

Hmm, it seems all the references I can find to this in the official VMWare documentation only actually mention using external JBOD storage for blade servers, not standard rack servers. For example in http://www.vmware.com/files/pdf/products/vsan/VMware_Virtual_SAN_Whats_New.pdf‌ it states "Support for High Density Storage Systems with Direct-Attached JBOD – Manage externally connected disk enclosures and leverage existing investment in blade-based architectures"

However I can find no reference to the approved hardware to make this work. Most blade server systems I know of (E.G. Dell M1000e) have proprietary backplanes that connect the blades to external ports using proprietary I/O modules. These modules are available in standard protocols like FC, Infiniband or Ethernet. As there is no exposed PCIe bus the only way I can see to connect a JBOD would be for the manufacturer or a third-party to build and ship an SAS/SATA I/O module of some kind and for the blades' BIOS to support this connectivity. (Assuming you don't want to go messing around with some kind fancy/schmancy Storage Over Ethernet setup.)

For a regular rack server it would seem much simpler; just install a SAS/SATA HBA and connect it via an external cable to the JBOD's backplane. Technically this is identical to connecting the internal SAS/SATA backplane of a server to the internal ports of an HBA.

[jonretting]

Thanks for your post, very informative.

On HBAs with no external SAS capability, I have tried SATA 7-Pin to SAS SFF-8088 adapters with no joy (IT mode) on LSI 2308.

Cheers

[jwhitehv]

I've definitely seen a slide which called out Dell's FX2 and IBM (DS8000? Don't remember) as the qualified JBOD expansion units. But that's not the same thing as being on the HCL. And Dell FX2 isn't exactly something one would use to extend storage to anything other than nodes in the same FX2 chassis.

[DanielSalzedoSA]

Yes, I found a whitepaper from Principled Technologies listing a VSAN 1.0/5.5 configuration on VSPhere v5.5 using the Dell FX2 enclosure, FX430 blade servers and FD332 storage units: http://www.principledtechnologies.com/Dell/PowerEdge_FX2_FC430_VMware_VSAN_VDI_0215_v4.pdf.

Can anyone confirm if this is a VMware qualified and supported solution or just a proof-of-concept and/or marketing exercise?

However even if it is this is again a proprietary system that requires a fork-lift upgrade and ties you in to another proprietary server hardware infrastructure. It is useless for existing servers that may be perfectly adequate for VSAN except for limited local disk space.

[DanielSalzedoSA]

Are there any updates on this from VMware now that VSAN 6.1 is released?

Thanks,

Daniel.

[depping]

Dell FX2 is on the HCL as it stands today as a certified solution using the storage blades Dell has.