The purpose of this blog is to highlight what you need to know about the IBM i POWER (AS400/iSeries) RAID controller cache and battery. I wrote this because I had 3 customers encounter cache battery problems in the last 7 days (yikes). I want IBM i users to understand what the cache battery is and how to respond when you get that first error message that lets you know to replace…not the one that tells you that your cache battery has died. Disclaimer: AS400, iSeries, and POWER are IBM servers. … [Read more...]
What Is A RAID Cache Battery, Anyway?
As you probably know, a RAID disk controller is a system failsafe feature that allows for a disk in a disk array to fail without bringing the system down. Built into the RAID controller is a buffer. The buffer “tells” the processor that the “data write-to-disk” is complete, so the system “knows” to go back to the processor to fetch more data to send to the disks. Quite simply, the cache buffer speeds up data from the processor to the disk. And this cache buffer has a battery to keep … [Read more...]