Monitor REC_CACHE_MEM_SIZE_MISMATCH (231)

The two controllers in the storage array have different cache memory capacities.

Cache Memory Mismatch

What Caused the Problem?

There is a mismatch in the cache memory for the storage array. This problem can occur for the following reasons:

Two controllers have different sizes of total installed cache memory. For example, Controller A has 2GB of total cache memory and Controller B has 4GB of total cache memory.
Two controllers have the same size of total installed cache memory, but there is probably a BIOS version mismatch.
There is a mismatch in the attributes of the cache memory between the two controllers (such as the buffer layout version, raw pool sizes, or Error Detection Coding (EDC) enabled values).

Important Notes

This problem typically occurs when you replace a controller that has a different type or size of memory than the controller that remained in the storage array.
This problem can also occur if the cache memory DIMMs were replaced. Replacing or changing the size of the cache memory inside a controller is typically not a supported operation.
Until this problem is corrected, write caching (including caching with mirroring) will be disabled.
If the two controllers have different sizes of total installed cache memory, the storage array will use the smaller capacity of cache memory between the two controllers. For example, if Controller A has 2GB of total cache memory and Controller B has 4GB of total cache memory, then both controllers will only use 2GB.

Recovery Steps

Record the total cache memory size for each controller:

Select the

Monitor > Reports > Storage Array Profile

menu option.

Select the

Hardware

tab, and then the

Controllers

tab.

Scroll down and locate the "Total data cache" field for each controller.

If...

Then...

The total cache memory sizes for the controllers are different

Go to step 2.

The total cache memory sizes for the controllers are same, but there is probably a BIOS version mismatch

You will need assistance from your Technical Support Representative to resolve this problem. Perform the following steps:

a	Select the Monitor > Health > Collect Support Data Manually menu option from the Array Management Window (AMW), and take the appropriate steps to save the support data to a .zip file.
b	Contact your Technical Support Representative and indicate that an "Cache Memory Size Mismatch" problem is being reported. Send the file you saved to your representative and wait for further instruction. Do not continue with the remaining recovery steps.

If...

Then...

You know which controller you want to remove from the storage array (the controller that has the cache memory size you DO NOT want to keep)

Go to step 3.

You do NOT know which controller you want to remove from the storage array

You will need assistance from your Technical Support Representative to resolve this problem. Perform the following steps:

a	Select the Monitor > Health > Collect Support Data Manually menu option from the Array Management Window (AMW), and take the appropriate steps to save the support data to a .zip file.
b	Contact your Technical Support Representative and indicate that an "Cache Memory Size Mismatch" problem is being reported. Send the file you saved to your representative and wait for further instruction. Do not continue with the remaining recovery steps.

Obtain a replacement controller that has the same sub-model and memory size as the controller you are leaving in the storage array.

Place the controller you want to remove offline:

Select the controller on the

Hardware

tab of the Array Management Window.

Select the

Hardware > Controller > Advanced > Place > Offline

menu option.

Follow the instructions in the dialog, then click the

Yes

button.

Read all of the following steps before taking any action. The remaining recovery steps will no longer be accessible from the Recovery Guru dialog after you complete step a.

Click the

Recheck

button to rerun the Recovery Guru.

Select the "Offline Controller" problem that is being reported in the Summary area.

Complete the recovery steps in the "Offline Controller" recovery procedure to replace the affected controller.

Click

Recheck

to rerun the Recovery Guru. The failure should no longer appear in the Summary area. If the failure appears again, contact your Technical Support Representative.

NetAppSANtricity.FailureID_0231_Monitor (UnitMonitor)

Knowledge Base article:

Cache Memory Mismatch

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