Q:

Ephemeral disk on Azure LS series

I am little confused about the ephemeral disk on LS series Azure VM.I want to suggest  L32s_v2 series vm for a customer due to high iops and throughput that the nvme disks provide but there is a catch. if vm is stopped from portal all the data on nvme disk will be erased. this is a serious risk because i cant use it for sql server database files

A:

eckes is correct, you can't use the NVMe disks for persistent databases. 
For the time being Premium SSD will be your best option for IOPs/throughput on data disks.  Ultra SSDs are in Preview now in East US2. 

+----------------+---------------------------------+------------------------------------------------+----------------------------------------------------------------+-----------------------------------------+
|                |       Ultra SSD (preview)       |                  Premium SSD                   |                          Standard SSD                          |              Standard HDD               |
+----------------+---------------------------------+------------------------------------------------+----------------------------------------------------------------+-----------------------------------------+
| Disk type      | SSD                             | SSD                                            | SSD                                                            | HDD                                     |
| Scenario       | IO-intensive workloads          | Production and performance sensitive workloads | Web servers, lightly used enterprise applications and dev/test | Backup, non-critical, infrequent access |
| Disk size      | 65,536 gibibyte (GiB) (Preview) | 4,095 GiB (GA), 32,767 GiB (Preview)           | 4,095 (GA) GiB, 32,767 GiB (Preview)                           | 4,095 GiB (GA), 32,767 GiB (Preview)    |
| Max throughput | 2,000 MiB/s (Preview)           | 250 (GA) MiB/s, 750 MiB/s (Preview)            | 60 MiB/s (GA), 500 MiB/s (Preview)                             | 60 Mib/s (GA), 500 MiB/s (Preview)      |
| Max IOPS       | 160,000 (Preview)               | 7500 (GA), 20,000 (Preview)                    | 500 (GA), 2,000 (Preview)                                      | 500 (GA), 2,000 (Preview)               |
+----------------+---------------------------------+------------------------------------------------+----------------------------------------------------------------+-----------------------------------------+

