Hello RRR , for me from the begining is to not have RDM for problems with DRS , backups , and the rest of the know issues for RDM.
The best practices for me to implement on VNX is to have failover mode 4 ( ALUA ) with Fixed for the policy path selection by the side of VMware. On VMAX we are using as failover mode Active/Active form the side of the VMAX and Round Robin by the side of VMware.
To improve the performance of the VMs that runs DBs the best practices to implement are many for example:
1 - You can put for the disks of the vms when the DBs are allocated and all the disk on the vm Paravirtualized adapters for SCSI PVSCSI.
2 - Its very important that you format the vmware disks with thick Provision Eager Zeroed to have a better performance by the side of the DBs.
3- Place binary SQL Server, log, and data in separate VMDK. In addition to better performance, separate them provides better flexibility to backup OS / SQL Server binary VMK can be backed up with snapshot-based backup and data recovery with vmware. The SQL Server data and log files can be guarded with backup solutions based traditional data.
4- If you have the chance to use powerpath its the best option to manage the multipath history.
5- Typical SQL Server Disk Access Patterns:
Operation Random/Sequential Rear/Write Size Range
OLTP - Log Sequential Write Up to 64K
OLTP - Data Random Read/Write 8k
Bulk Insert Sequential Write Any multiple of 8k up to 256k
Read Ahead (DSS, Read Read any multiple of 8kb up to 512k Index Scans)
Backup Sequential Read 1MB
We have a lot of best practices to implement by the side of the VNX/VMAX , VMware and the DBs world too but these are a resume of the best for me.
If you need more specific information please do not hesitate to contact me.
Thanks & Regards