Search This Blog

Thursday, March 12, 2015

Cisco FlexFlash and it's Role

So the customer I replaced the RAID controller for as well as upgraded their CIMC is asking how to use the FlexFlash and how to get a second card.  I did some research and found that if you already have one then adding a second 16 GB by ordering directly from Cisco is easy.  You cannot use third party SD cards, or at least it isn't supported and the only benefit from having a second one is RAID 1.
For those of you that arn't familiar with RAID, basically each RAID level defined does something with storage.  RAID 0 is striping where it takes two drives and turns them into one with better performance.  The caveat to this is, if one drive fails, your entire system dumps. This isn't a big deal in a lab or non-production environment but on a server, hell to the no....  RAID 10 also known as RAID 1+0 would be your go to level if you wanted expanded storage as well as redundancy.  Basically it takes RAID 1 and 0 and combines them.  RAID 1 is mirroring.  Mirroring does exactly what you would think, it duplicates the drive to another providing redundancy in the event of a backup.  With RAID 10, you have striping and mirroring for the ultimate setup.

The Flexflash contains 4 partitions and on the newer versions 1.5+ I believe they reduced this to one partition.  Each partition has a different utility.  Firmware, upgrades, drivers for the chassis itself, and a lone partition for whatever you want to use it for.  The link provided is a more in depth understanding of what the FlexFlash is and does.

http://www.cisco.com/c/dam/en/us/solutions/collateral/data-center-virtualization/unified-computing/whitepaper_C11-718938.pdf

In the end you need to use the SCU on the existing SD card to set up the new one.  This will let you get the RAID going as well as verify everything is in proper working order.  I would take it one step further and make sure everything is on the latest release and keep a backup release that you know works on the last partition just so you got something to work with.  SCU stands for Server Configuration Utility by the way.  It's basically a GUI driven bootable image on the SD card that makes life easy.  Who wants to dig around the BIOS setting stuff up like its 1999?

Below are some additional links I found useful on FlexFlash:

https://supportforums.cisco.com/discussion/12421051/flexflash-questions

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/release/notes/OL-32097-01.html#pgfId-125827

http://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/hw/C220/install/C220/replace.html

https://supportforums.cisco.com/discussion/12002036/flexflash-vs-usb-esxi-install

http://www.cisco.com/en/US/docs/unified_computing/ucs/c/sw/gui/config/guide/1.5/b_Cisco_UCS_C-series_GUI_Configuration_Guide.151_chapter_011.html#concept_7DC7EAB11DCA4B4D8F08F697398A960E

As always, I hope this blog post was helpful.  Still not a lot of views and no comments.  Hopefully that changes within the next few months.  I really want this blog to turn into something helpful and a one stop source for those on off situations where Cisco isn't of much help unless you get in contact with TAC.  Since Smartnet is expensive, this could be a temporary filler.

No comments:

Post a Comment