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M3 Blades SD support - Things to know before deployment...

Keny Perez

Hello "Neighbors" of the community!

I have lately seen how different users, partners and colleagues have been having troubles identifying if an SD card complies with all requirements to be supported for a blade server, so here is a checklist of items you need to check when you are planning to use SD cards.

{DISCLAIMER} ALL this information is from the release notes and configuration guides.  The idea is just to provide a checklist so that you do not have to look for all documents or open a TAC case to find out you are doing/deploying something unsupported.

  • SD cards are supported starting with UCSM 2.1(2a)
  • The PID is UCS-SD-16G and its size is 16GB (this is the only one in this moment)
  • The Flex Flash has ONLY 1 partition, unlike C series, this cards only has the HV partition:

From:   The FlexFlash SD cards shipped with supported B-series servers only have an HV partition

  •   this shows how to enable/disable the SD card 
  • Once the HV partition is enabled, UCSM will show it as a USB drive to the BIOS AND to the host OS, this also means that the SD card cannot be used like a portable datastore for ESXi (cause it is no supported) but can be used as a USB for a VM for example.

  • Hardware information and inventory data about the controller and SD cards is not collected.
  • Monitoring of the controller and SD card status or health is not supported. If FlexFlash controller or SD card fails, no faults or errors will be displayed in UCSM.

  • Formatting of the SD cards is not supported.
  • To manually boot from the HV partition, Local Disk should be present in the boot policy used in the Service Profile, and be launched from the BIOS boot menu (F6)

  • If a server is not capable of supporting SD cards or has an older CIMC version, the service profile association will FAIL.
  • If you disable the FlexFlash option in a supported server, a host reboot will be triggered and a reboot warning message displayed. << Be carefull with production environments and,  if possible, have your maintenance policy set to “User Ack” to avoid inconveniences.

  • Although 2.1 begins to enable mix between bundle software (Infrastructure and server bundle), enablement/support for SD card is an exception meaning you need the proper 2.1(2a) everywhere to enable the SD card

  • Be aware of the following known limitations in UCSM 2.1 (, but since this is from the Release Notes, be sure to      check the bug directly or Release Notes of future releases:

*CSCug32086 The B420 M3 blade server with an SD card freezes after running for one day on ESXi 5.0 << This issue has no known workaround. 1st found in 2.1(2a)B

*CSCuf77316 Windows 2012 installed on SD flash running Cisco UCS Release 2.1(2a) fails MSFT certification <<This issue has no known workaround. 1st found in 2.1(2a)B

  • Even though the servers have 2 SD slots, it ONLY supports one card now, mirroring/dual SD cards on the M3 blades will be      supported in future releases.  This      is the same way it began on C-series servers so be a little patient, we are working on adding that


I hope this helps you avoid a few headaches and love even more our UCS Data Center Solution.

Comments are always welcome!



Hi Keny, We having issue where ESXi loss connectivity with SD Card, I have seen your post on it here, I tried to reset CMIC controller, but it doesn't help. After reboot, it loss all the confiugration, this is very frustrating. I have opened the case with Cisco. Any update when they are going to roll out fix for this ?

Keny Perez

Hi Vasim,

Thanks for reading the blog.

The issue you are facing is also on a B series server or on a C series? As you saw in that post you mentioned, I said that we are currently working on that for C series. On B series we have seen that only in environments where one of the items I mentione above is not met; for example not the required UCSM firmware or old CIMC version, so we have not had a chance to see someone that is really deploying the SD card with all the required item and having issues.

Let me know what kind of server you have and I will see how I can help you , your case # in a private message might also help me


Keny Perez


In the TAC case you opened, ask your Cisco Engineer to take a look at  CSCui77602


Keny Perez

Hi All,

For those  of you following this thread, the release 1.5(3d) for C series includes the fix for this issue:

Release 1.5(3d)

Following defects were resolved in Release 1.5(3d):


Symptom    C-series M3 intermittently losing access to flexflash and SD card.

Workaround   Reset the flexflash controller from WEBUI/CLI or reboot CIMC. (CSCuh33982)

Download it from here:

The patch for CSCui77602 (B-series server SD card bug) should be out shortly and it will be anounced soon, I will keep you all posted.


Keny Perez

The issue with the SD cards on B series has been solved, see the thread for the steps to solve this issue


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