Got a few questions about this and configuring via ACU.
1) Physical Drive Write Cache. Can you explain what this is? Is it the actual physical drive write cache and nothing to do with the array accelerator?
Also, am I right in saying the accelerator battery has no effect on this. i.e. if you lose power you may have problems?
2) Ratio settings. 25/75 Read/Write seems to be the default. Do you have any guidelines on correct use of this ratio?
In real world, what sort of improvements, if any, would you expect to see, for exampe, for a RAID1 configured windows system disk?
3) If battery is fault, am I right in saying that write cache only gets disabled (in effect, switches to 100/0 Read)? Or does it turn off acceleration for read also?
4) Have various levels of firmware and ACU installed on many servers. Some have the option to "Enable Write Cache when Battery/Capacitor Not Present or Not Completely Charged" but some have this option missing. Can you confirm whether a minimum level of firmware is required for this functionality?