ProLiant Servers (ML,DL,SL)

No-Battery Write Cache enable after smart array battery fail

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No-Battery Write Cache enable after smart array battery fail

Hello all,

We have a lot of DL380 gen9, and now their batteries are failing.

I know the risk with No-Battery Write Cache from document as follow:

No-Battery Write Cache:
If you have no battery installed or it is failed you can enable this feature to use the on-board cache of the raid controller.
But if the server is not protected via UPS and looses power. Data in the cache will be lost and cause data corruption on the hard drive.

I got the command to config it to enable:

Enable smart array write cache when no battery is present (No-Battery Write Cache option) Values are Enable or Disable.
ssacli ctrl slot=0 modify nbwc=enable

I wish to know if any parameter need to change?

# hpssacli
>ctrl slot=0 show

Smart Array P440ar in Slot 0 (Embedded)
Bus Interface: PCI
Slot: 0
Cache Serial Number: XXXXXXXXXXXX
RAID 6 (ADG) Status: Enabled
Controller Status: OK
Hardware Revision: B
Firmware Version: 6.88
Rebuild Priority: High
Expand Priority: Medium
Surface Scan Delay: 3 secs
Surface Scan Mode: Idle
Parallel Surface Scan Supported: Yes
Current Parallel Surface Scan Count: 1
Max Parallel Surface Scan Count: 16
Queue Depth: Automatic
Monitor and Performance Delay: 60 min
Elevator Sort: Enabled
Degraded Performance Optimization: Disabled
Inconsistency Repair Policy: Disabled
Wait for Cache Room: Disabled
Surface Analysis Inconsistency Notification: Disable
Post Prompt Timeout: 15 secs
Cache Board Present: True
Cache Status: OK
Cache Ratio: 10% Read I 90% Write
Drive Write Cache: Enabled
Total Cache Size: 2.e GB
Total Cache Memory Available: 1.8 GB
No-Battery Write Cache: Enabled
SSD Caching RAID5 WriteBack Enabled: True
SSD Caching Version: 2
Cache Backup Power Source: Batteries
Battery/Capacitor Count: 1
Battery/Capacitor Status; Ok
SATA NCQ Supported: True



Re: No-Battery Write Cache enable after smart array battery fail


As of now, no change is required. Cache Ratio is already: 10% Read | 90% Write

The same change can be done from SSA GUI Page#38

However, as per output shared its seen that No-Battery Write Cache is already enabled for the particular node and Battery/Capacitor Status; Ok


I am an HPE employee
Accept or Kudo