hp 6402 raid card modify cache enable

[白眉大侠]

I am a hp 6402 raid card,I run command saconfig:
# saconfig /dev/ciss4

******************** SmartArray RAID Controller /dev/ciss4 ********************

Auto-Fail Missing Disks at Boot = enabled
Cache Configuration Status = write cache temporarily disabled (code=1)
Cache Ratio = 75% Read / 25% Write

---------- PHYSICAL DRIVES ----------

Location Ch ID Size Status

External 2 0 73.4 GB OK
External 2 2 73.4 GB OK
External 2 4 73.4 GB UNASSIGNED

---------- LOGICAL DRIVE 0 ----------

Device File = c4t0d0
RAID Level = 1+0
Size = 70001 MB
Stripe Size = 128 KB
Status = OK

Participating Physical Drive(s):

Ch ID

2 0
2 2

Participating Spare Drive(s):

None

# saconfig /dev/ciss4

******************** SmartArray RAID Controller /dev/ciss4 ********************

Auto-Fail Missing Disks at Boot = enabled
Cache Configuration Status = write cache temporarily disabled (code=1)
Cache Ratio = 75% Read / 25% Write

---------- PHYSICAL DRIVES ----------

Location Ch ID Size Status

External 2 0 73.4 GB OK
External 2 2 73.4 GB OK
External 2 4 73.4 GB UNASSIGNED

---------- LOGICAL DRIVE 0 ----------

Device File = c4t0d0
RAID Level = 1+0
Size = 70001 MB
Stripe Size = 128 KB
Status = OK

Participating Physical Drive(s):

Ch ID

2 0
2 2

Participating Spare Drive(s):

None
I would like to add a hard drive to RAID in the present，I run command:
# saconfig /dev/ciss4 -E 0 -p 2:4
Operation can't be performed with cache disabled
saconfig (/dev/ciss4): Current driver state is READY
I do not know how to modify the CACHE ENABLE。

[Torsten.]

Please provide

# sautil /dev/ciss4



Note this:

Cache Configuration Status = write cache temporarily disabled (code=1)


temporarily !!!!


This usually means you have a bad battery.

[白眉大侠]

I replaced a new battery, but still the same situationã

[Torsten.]

Please provide

# sautil /dev/ciss4

[白眉大侠]

HELLO,thanks,I have replaced the two batteries on the card can now be normal operationï¼
I just do not understand this card must be two batteries before they can work?

[Dennis Handly]

>I just do not understand this card must be two batteries before they can work?

For a write cache, if you don't have batteries, you could be losing lots of data if the power goes out.
I.e. the controller is lying to the OS in saying the data is written to the disk and the OS makes reliability assumptions based on that.

[Torsten.]

You have cache on the controller itself (64MB) and on the expansion card.