Hi
We have just setup a 2 node W2019 cluster (Fully Patched/Latest Drivers connected with 2 x DL360 Gen 8 servers to a MSA 2050 ISCSI (8 x 1GB, 4 Per Controller) Following the best practice guide. Everything is working ok, validation fine and tested with two VMs failing over etc. We have obsevered two things.
1) When copying VMs to Volumes we see the odd ICMP Ping drop to the controller IPs? All 4 don't drop at once so wasn't sure if this was the controller using MPIO to load balance? We can't see any drops or errors on connected switch ports to the MSA SAN.
2) The best practice guide says,
Default mappings for volumes
By default, the HPE MSA maps all connected initiators to all volumes/volume groups. Therefore, all hosts/host groups have the ability to access
all volumes using the specified access mode, LUN, and port settings. This is considered the default mapping.
The advantage of the default mapping is that all connected hosts can discover all volumes and volume groups with no additional work by the
administrator. The disadvantage is that all connected hosts can discover volumes with no restrictions. Therefore, this process is not
recommended for specialized volumes, which require restricted access. In clustered environments, to avoid multiple hosts mounting the volume
and causing corruption, the hosts must be cooperatively managed using cluster software.
You can change the default mapping of a volume, or create, modify, and delete explicit mappings. A mapping can specify read-write, read-only, or
no access to a volume through one or more controller host ports. When a mapping specifies no access, the volume is masked.
When creating an explicit mapping from a host/host group to a volume/volume group, a LUN identifier is established. A LUN identifies a mapped
volume to a host. Both controllers share a set of LUNs, and any unused LUN can be assigned to a mapping. However, each LUN can only be used
once as a default LUN. For example, if LUN 5 is the default for Volume 1, no other volume in the storage system can use LUN 5 as its default
LUN. For explicit mappings, the rules differ: LUNs used in default mappings can be reused in explicit mappings for other volumes and other
hosts.
My question is if you have for example 3 volumes and 3 hosts, should volume 1 be connected to all hosts on LUN 1, volume 2 be connected to all hosts on LUN 2, Volume 3 be connected to all hosts on LUN3?
Thanks
Michael
