[Info-vax] Hypervisors and clusters

[Stephen Hoffman]

On 2021-01-23 01:11:52 +0000, Mark Berryman said:

> As far as I know, there are currently only two ways to build a VMS 
> cluster where every node has direct access to storage - either a shared 
> SCSI cluster or using SAN-based storage.

The other supported cluster storage interconnects known to OpenVMS are 
nearly gone, gone, or long gone, yes. And multi-initiator SCSI is very 
nearly gone.

And I'd be shocked to see an SMB client integrated into OpenVMS and clustering.

Closer to the I/O that OpenVMS has traditionally supported, IBM 
supports high-availability configurations using multi-initiator SAS 
controllers and HACMP, though I'm unfamiliar with the details and 
features and limitation of that IBM gear.

And also closer to traditional OpenVMS I/O, iSCSI HBA support.

> I can't use a NAS because the only protocols on a NAS that present a 
> raw disk to the host are iSCSI and fibre channel.  If I try to run the 
> iSCSI initiator on a current version VMS, it crashes the system.  If 
> there is a NAS out there that offers fibre channel support usable by 
> VMS, I haven't found it.
> 
> My cluster is currently SAN-based.  That means that all disks are named 
> $1$DGAn:  That means that, in order for a virtual host to join this 
> cluster and have direct access to the storage, the virtual host has to 
> think it is talking to an HBA.  It can't be something mapped to a disk 
> available to the host system.  Are there any hypervisors out there that 
> will pass access to a local HBA directly to the guest host?  If so, 
> does the guest host need a driver for that specific HBA or does the 
> hypervisor map it somehow?
> 
> My specific situation:
> 
> All of my non-VMS systems are Macs.  I have no Windows, Linux, or other 
> systems.  The HBA on the Macs is plugged into a thunderbolt port.  Now, 
> since I doubt thunderbolt support is being added to VMS as part of the 
> port, I'm wondering if a virtual host is going to work for me.

USB4 on USB-C is Thunderbolt 3. Now whether VSI adds native support for 
that? Hypervisor vendors will undoubtedly continue to add USB4 support 
for various I/O devices, too.

Some potential NAS options, as you haven't listed which NAS devices 
you've tried...

TrueNAS (née FreeNAS) has added Fibre Channel support:
https://www.truenas.com/community/threads/updated-guide-for-fibre-channel-on-freenas-11-1u4.63464/ 

https://www.truenas.com/community/resources/fibre-channel-on-freenas-11-1u4.93/

Upcoming Fibre Channel support with Synology NAS, and the DSM 7.0 beta:
https://www.synology.com/en-us/company/news/article/2021_AND_BEYOND_Main/Synology%202021:%20DSM%207.0%20Beta%20and%20the%20future%20of%20data%20management 


I suspect VSI will be busy with these and other issues and support 
details and related docs, particularly after OpenVMS V9.1 gets 
installed and folks start poking at the options and configurations past 
those that VSI has tested.

FWIW: Website for information on VMware configurations running on Mac: 
https://www.virtuallyghetto.com

TL;DR: We will all learn more about OpenVMS x86-64 and clustering 
between now and V9.2.  I suspect VSI doesn't yet know the answer to 
some of these details. And some will be learned from various of us 
testing these configurations.


-- 
Pure Personal Opinion | HoffmanLabs LLC