This way you can see if the battery backup is speeding up your server, on this server it is working:
root@server:~# omreport storage vdisk
List of Virtual Disks in the System
Controller PERC H700 Adapter (Slot 1)
ID : 0
Status : Ok
Name : VD1
State : Ready
Hot Spare Policy violated : Not Assigned
Encrypted : Not Applicable
Layout : RAID-5
Size : 1,862.00 GB (1999307276288 bytes)
Device Name : /dev/sda
Bus Protocol : SATA
Media : HDD
Read Policy : Adaptive Read Ahead
Write Policy : Write Back
Cache Policy : Not Applicable
Stripe Element Size : 64 KB
Disk Cache Policy : Enabled
The important line here is the
Write Policy : Write Back
Make sure you have a battery before enabling this, using:
root@server:~# omreport storage battery
Then you can enable using:
root@server:~# omconfig storage vdisk controller=0 vdisk=0 action=changepolicy writepolicy=wb