We're running a huge SAP HANA workload in a VM deployed in a public cloud. The VM has 3.8 TB of memory and 128 cpus.
We have been hit with very slow disk throughput in the data disks - this is where the database persistence resides. Now Hana being an in-memory database, frequently persists data from the memory to the data disks to insure against data loss. One of the measures suggested was to increase the size of the root disk to 1 TB in order to achieve a higher IOPS. I would like to seek your opinion if this indeed could improve the overall performance of the VM. Or, does anyone here have a similar experience. The OS is SUSE linux 12 SP3. The kernel version is 4.4.162