Disk Group Policy - What is Platform Default?

[Stephan Perschke]

Hi,

we are starting to use Disk Group Policies and Storage Profiles. This is a pretty cool feature. Looking at Disk Group Policies I have the option to specify some very specific configuration items or just use the "Platform Default". As we are using different RAID controllers and SAS HBAs with different capabilities it would be more flexible to keep the "Platform Default" but what is the default for my controller? Is it possible to manipulate the default settings?

Cisco UCS Manager offers a pretty good solution for BIOS settings. You can define your BIOS setting very ganular, or you can keep the Platform Defaults that are defined in the "BIOS Default" policies in the root organization. Furthermore it is possible to modify the Platform Defaults. I was searching for something similar for Disk Group Defaults but didn't find it so far.

Can you point me to the correct location?

Kind regards,
Stephan

[Walter Dey]

Hi Stephan

I would never modify any default bios policies, because during a firmware upgrade, they will be overwritten.

Platform default simply applies for the hardware model (e.g. B200-M4).

If you need different bios setting, create your own policy !

Walter.

[Stephan Perschke]

Hi Walter,

thank you for sharing your opinion with me. Actually we never changed the BIOS defaults. However, I like the possibility to see the default settings and to change them if required.

However, here I'm looking for the default settings for Disk Groups. If UCS Manager does not provide the information, maybe it is documented somewhere.

Kind regards,
Stephan

[kevin.tunge]

On a more general level, but germane to your question- I would like a reference of what ALL the Platform Defaults are for any UCS server I'm looking for. Like you, I currently have a BIOS policy with a few parameters marked as 'Platform Default', and I'd like to know what option that default is actually using.

Stephan, did you ever find out where this is documented?

[Kirk J]

Greetings.

Under the Policies,Root, BIOS Defaults, are listed all the various supported C and B series servers, and each one's bios default settings.

Thanks,

Kirk

[Stephan Perschke]

Hi Kirk,

I checked UCSM again, but the BIOS Defaults do not list the Platform Defaults for Storage Controllers, like the LSI MegaRAID 9271-8i.

Kind regards,
Stephan

[Stephan Perschke]

Hello Kevin,

Unfortunately I never found the 'Platform Defaults' for Storage Controllers in UCSM. Today we are using version 3.1(2b). That is really a pitty as from my experience 'Platform Defaults' can be quite different. On the C240 M3 server with a LSI MegaRAID 9271-8i Controller the default write Cache policy is "Write Back Good BBU", while it is "Write Throu" on the C240 M4 coming with a Cisco RAID controller.

Kind regards,
Stephan

[itm.i11.team]

There are some defaults in the UCS Servers RAID Guide e.g. the LSI MegaRAID:

https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/sw/raid/configuration/guide/RAID_GUIDE/MegaRAID.html

However I have not found any server type specific information.

[Kirk J]

On the M3/92xx controllers the defaults were write-back cache, read ahead caching enabled.

On the M4 and later with 12Gb controllers, the defaults for storage are set to write-through, and are more SSD centric for defaults.

Thanks,

Kirk...