Add 'detail' to the command below for more detail.
# hpssacli controller slot=1 show config Smart Array P222 in Slot 1 (sn: PDSXH0BRH6E0ZP) array A (SAS, Unused Space: 0 MB) logicaldrive 1 (558.7 GB, RAID 1+0, OK) physicaldrive 2I:1:1 (port 2I:box 1:bay 1, SAS, 300 GB, OK) physicaldrive 2I:1:2 (port 2I:box 1:bay 2, SAS, 300 GB, OK) physicaldrive 2I:1:3 (port 2I:box 1:bay 3, SAS, 300 GB, OK) physicaldrive 2I:1:4 (port 2I:box 1:bay 4, SAS, 300 GB, OK) SEP (Vendor ID PMCSIERA, Model SRCv8x6G) 380 (WWID: 50014380305FB0DF)
# hpssacli controller slot=1 show status Smart Array P222 in Slot 1 Controller Status: OK Cache Status: OK Battery/Capacitor Status: OK
CAUTION: Because physical drive write cache is not battery-backed, you could lose data if a power failure occurs during a write process. To minimize this possibility, use a backup power supply“
# hpssacli controller slot=1 show config detail |grep -i cache Cache Serial Number: PBKUA0BRH6E54G Wait for Cache Room: Disabled Cache Board Present: True Cache Status: OK Cache Ratio: 25% Read / 75% Write Drive Write Cache: Disabled Total Cache Size: 512 MB Total Cache Memory Available: 304 MB No-Battery Write Cache: Disabled Cache Backup Power Source: Capacitors Cache Module Temperature (C): 35
# hpssacli controller slot=1 modify dwc=enable Warning: Without the proper safety precautions, use of write cache on physical drives could cause data loss in the event of power failure. To ensure data is properly protected, use redundant power supplies and Uninterruptible Power Supplies. Also, if you have multiple storage enclosures, all data should be mirrored across them. Use of this feature is not recommended unless these precautions are followed. Continue? (y/n)