UCS C220 M3 with MegaRAID 9266-8i - cache degraded

[jstrittmatter]

Hello,

I have a UCS C220 M3 running BiOS 1.5.1g and CIMC firmware 1.5.1f.

There is a LSI MegaRaid 9266-8i (Firmware 23.9.0-0023) controller with super-cap inside.

CIMC sais that the virtual drive has a moderate fault state, cache is degraded and capacitance is at 0%. Current cache policy is on write through instead of configured write back.

Is this a case for Cisco TAC?

[Vaijanath Sonvane]

Hi,

The warning message appears if you do not have a Battery BAckup Unit Instllated on the server. I just worked with Cisco TAC and following is the solution.:

1. Launch KVM Console of the server

2. Power Cycle the Server

3. When LSI RAID configuration window displays, press CTRL+H and start the RAID Configuration Utility.

4. Click on Virtual Drive. Example Virtual Drive 0.

5. Change Default Write Mode to "Write Through" and click "Change"

6. Press "Yes" to take the effect.

7. Exit from RAID Configuration Utility nad restart the server.

[Keny Perez]

Vaijanath,

Thanks for the feedback, that is definitely something that needs to be checked first. If you have an alarm for something not present you may get this type of false-positive (in your case) and forcing the controller to use a write mode of "write back" will make your controller write the info in cache and eventually move that data to the disks which is totally risky in case of power loss, that is the reason for the alarm you saw and also the reason why you were asked to move to write-through so the data can be written to disks right away. 

The draw back in write through mode is that writtting to disk is slower that writting to cache, so if you have high I/Os you can definitely be affected, but if you do NOT have to many I/Os then you should be fine.

Rate ALL helpful answers.

-Kenny

[Claudio Quiroz Cabello]

Hello Friends,

I have the same issue too. You should go to replace the SCP module in UCS. You can see the storage logs and they show battery warning. The part number is:

UCS-RAID-CV-SC=

Best Regards,

Eng. Claudio Quiroz Cabello

[lowfell]

I have this same issue now, we are awting a server rebuild within the next couple of weeks, can this wait till then or does it require urgent attention?

[Claudio Quiroz Cabello]

Lowfell

If you have SCP issue, you can wait for the rebuild, because is only power backup of LSI MegaRAID card

[lowfell]

Hello . The rebuild was actually a different Chassis. So, i got the customer to reboot the CIMC, but we still see the error.

Should we now open a TAC Case?