Cisco UCS M4/M5 SD Boot

[joeharb]

We currently have a mixture of M4/M5 B200 blades (mostly M4) that are booting from SAN.  The boot luns are typically small (less than 10 GIG) but with the migration to ESXi 7.X we are concerned that the boot lun is not big enough according to specs even if the upgrade is successful.  We would like to explore migrating to local boot for these servers using SD/NVMe, but I think there is an issue with ESXi 7.0 and SD cards.  Another department within our company has migrated to NVMe (they only have M5's deployed) but I am not sure that is supported on the M4's.  We could also look at getting new boot LUN's created that have enough storage (which is great for refreshes) but either way would force for a reinstall of the host.

Is local boot (SD/NVMe) supported on the M4's and will we run into the ESXi SD issue?  How are others booting these blades?

Thanks,

Joe

[Steven Tardy]

Most of the things you are asking are covered on the B200 spec sheets (google: B200 M4 spec sheet).

For B200 M4, NVMe/M.2 were new-ish when M4 was released.
For B200 M4 I'd probably opt for the RAID controller and two SAS or SATA SSDs.
See the spec sheet caveats as there are some gotchas like:

• NVMe SFF 2.5" drives are not bootable.

For B200 M5, the M.2 boot drive is a great (and common) option.
For B200 M5 I'd probably opt for the M.2 single drive. This drive will need to be monitored by the OS as the single drive controller is a pass-through controller.
For B200 M5 there are two M.2 options:

• Single M.2 UCS-MSTOR-M2
• Dual M.2 RAID UCS-M2-HWRAID

As you mention VMware will no longer support SDCard in the near future (what Cisco UCS servers calls FlexFlash, aka bootable SDCard via USB.) so I would NOT recommend SDCard as a boot option today.
If you open a VMware case today one of the first things VMware support will say is "This boot device isn't supported" (even though it IS supported, just deprecated).