Dell Poweredge 2800 PERC 4e Cache Running Exchange 2003
Posted on 2009-04-20
I am running exchange server
2 physical disks in RAID1 configuration
A bit of background......
The server has been running fine for years (1 Storage Group, 1 mailbox store), however I have recently gone through the process of adding another RAID1 to increase space, I created 2nd and then 3rd storage groups on the new array. (I did Clear the config in the Perc Raid software (CTRL+M at boot and set it up again as it was)
This caused a severe degredation in performance.
I tried the 3G switch in the boot.ini file
Since then I have managed to reduce the mailboxes and have done a lot of moving mailboxes from one Storage Group to another, and from mailbox store to mailbox store.
I now have the original 2 physical disks in the server (RAID1) and have removed all the others I have split the data into 2 mailbox stores.but the perforamance is still very bad. I then tried splitting it accros storage groups....but still the same performance issue.
Working through the TroubleShooting Assistant for Exchange, It is highlighting bad disk performance....and using the performance monitor for Windows the Ave.Disk Sec/Read and Write graphs are spiking all over the place....sometimes the graph shows both these running constantly at 100....however occasionally the graphs go all quiet and performance is ok.
I have now removed the 3G switch in the boot.ini file.
The demand on the server shouldnt have changed considerably, the user count is similar to always, and I am runng nothing else on the server.
I wondered if by Clearing the RAID config and resetting it up i have disabled the cache, it is set to DirectIO at the moment in the RAID setup. Does this mean the Cache is on or off?
I dont know what else to do...it is difficult for me to reboot the server as it is used almost 24/7
Thanks for any help in advance.