A couple weeks ago we did a redeploy for a customer. They have a single server, Dell PowerEdge 1800 with dual 3 GHz Xeon processors, 4 GB RAM, and the Dell branded Adaptec CERC SATA controller with three 150 GB SATA disks originally configured with a 12 GB partition for system and around 200 GB in a RAID 1, this system before the redeploy ran Windows Server 2003 and Exchange 2003, and held the company's file share. We upgraded them to Windows Small Business Server 2003 R2 premium on this same hardware.
Post install of SBS we found that the consol was very sluggish, and users complained about speed. We looked at everything, NIC offload engine, SQL tuning, infrastructure hardware, the list goes on. Eventually it was determined that it had to be disk I/O that was the bottleneck. After searching the web it became apparent that the Dell branded Adaptec CERC controller that was installed with the machine was to blame.
To step back just a second, do you know what CERC stands for? I didn't not until investigating this issue. CERC stands for Cost Effective RAID Controller or Cheap Especially in RAID Controlling! I am sure this was a acronym created by a marketing department somewhere, because the next step up for a RAID controller in this system when new was a $2000 upgrade. I am sure calling the card a "CERC" helped sell it when stacked up next to the $2000 upgrade to a better controller.
To get back to the issue, we had used the CERC card and the three disks available to create a single RAID 5 logical disk and installed SBS and migrated the shared data to this logical disk. We did all the configuration and tuning and had already connected all client machines, and the customer was using the system, but it was slow, way slow, too slow.
The issue was thus: How do we replace the CERC card for a better RAID controller without having to do another 20 hour redeploy of SBS, just move the disks, no repartitioning, no formatting, not data loss?
Answer: just move the disks, just do it!
If the original array was created on an Adaptec controller, and the replacement is an Adaptec controller, the controller's BIOS understands the configuration created for the array from one controller to the next. I am not sure if this will work for any other vendors hardware but fortunately for us going from Adaptec to Adaptec it worked perfectly.
Here was our process.
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