On Wed, Jan 5, 2011 at 9:47 AM, mcclnx mcc <mcclnx at yahoo.com.tw> wrote: > we have several R900 servers with PERC 6/E card in it. Recently it we getting some message on /var/log/message say change to "write back" and change back to "write through". > > We figure out it is PERC 6/E card battery weak. My questions are: > > 1. some battery only use one year (some even shorter) and already this problem. > > 2. How come PERC 5/E does not have this issue? > > 3. where is DISK array information store for PERC 6/E? I did NOT see NVRAM on PERC 6/E card. > > 4. when replace PERC 6/E card and power on server sometime it will ask you "import configuration" ans some time it won't. Why? > > 5. When replace PERC 6/E card and power on. Server ask "import configuration" should I answer "yes"? > > 6. where can I find documentation which mention "import configuration"? > > Thanks. Please install and learn about the Dell Open Manage Monitoring tools, and also read user guide for PERC/6 on Dell's web site. You seem to be flying blind here and just guessing at what's going on. They have a yum repository where you can "yum install" the software. Most likely the card performed a "battery relearn" cycle where it discharges and recharges the battery. During this process the battery level drops and this causes the cache memory to become disabled. It also sounds like you already got some new cards, which may have been a waste of money. Install Dell OMSA, review the OpenManage status and logs, and probably send back the new cards you already bought (maybe your Dell sales rep will be upset that you learned how to do this instead of just buy new stuff from him).