Re: SCv3020 and SAS attachments with VMware questions
In the past 6-7 years we setup around 30-40 of these SAS storage system starting with PowerVault MD3 (32xx, 34xx) and than moving to SCv2020,3020 and even 5020 for customer who never have a need for more than 4 Hosts. vSphere supports this kind of setups for ages now.
Yes the 12G is slighly more than 8G FC and also lower latency.
Also on a modern SAS storage the LUNs are mapped to all connected Hosts so vMotion ,HA are working as expected. There is no different compared to FC or iSCSI and the way how to configure is the same and on SC its named "mapping".
Yes we use async. replication with SCv2020 and 5020 and both are running on SAS. A SAS version never can use sync. replication or live volume. Keep also in mind than RIRA licenses are needed and when speaking about 3020/5020 you need the mezz. card options because there are no dedicated Repl. ports anymore (like on SCv2020).
I think that we never go for the encryp. options because of the limited drive options. Also mixing encryp. and standard drives is not supportet. So think about if you would go this way.
A SC will try to write a stripe over 5 or 9 disks so this is why its called Raid5.5 or 5.9. The later one gives better space efficiency. If you select Double Redundancy (allows up to survive 2 disk failures at once) than the system use RAID6 with stripes over 6 or 10 disks.
The SC dont use fixed diskgroups like older storage systems. Instead it groups "similar" diskstypes into diskfolders (like a pool) and every volume(LUN) can use a different policy which can change as often and when ever you want. Also the SC used dyn. RAID level with RAID tiering based on the policy it starts with RAID10 and converts than to RAID5/6 with the option to migrate data (data progression) from Tier1 over Tier2 into Tier3.
 right now there is no way that a vSphere 6.5/7 together with a SAS SC works out of the box. The right driver needs to select manually and also a special command line option needs to be set. Yes, they have updated their vSphere Bestpractices guide a couple of weeks ago. But we had a hard time in the past months.
We and our customers like the SC with SAS!